-Cultural Evolution-

Society, Technology, Language, and Religion

 

Edited by Peter J. Richerson and Morton H. Christiansen

 

The MIT Press

Cambridge, Massachusetts

 

CHAPTER ONE: INTRODUCTION

By Peter J. Richerson and Morten H. Christiansen

Page 1

 

OBJECTIVES OF THE FORUM:

They had a retreat wherein they could discussion the state of the CULTURAL EVOLUTION field. This book is the result.

Gintis suggests gene-culture coevolution as a fulcrum for consilience.

 

WHY THE FOUR SECTIONS:

We better understand humans by applying the cultural evolutionary perspective to social systems, technology, language, and religion.   A question is do these areas of interest evolve in similar or different ways?  They aim at systematic answers.

 

3 – Is all descent with modification? Culture often produces more “reticulated phylogenies.”

Reticulated: constructed, arranged, or marked like a net or network. Phylogeny: the evolutionary history of a kind of organism

Biologists being overwhelmed by the complexity of networks is a comfort to those trying to get a handle on cultural reticulation.

 

WHAT IS CULTURAL EVOLUTION?

Culture definition: the ideas, skills, attitudes, and norms that people acquire by teaching, imitation, and / or other kinds of learning.

Cultural evolution: fundamentally, the change of culture over time.

4 – Tracking cultural evolution, they need a system to take account of frequency of a cultural variance.   Taxonomies work here.  But nothing is as clean as the “forces” of physics herein.

 

THE INVESTIGATION OF CULTURAL EVOLUTION: A BRIEF HISTORY

4 – Herodotus and Sima Qian in China. 

5 – Philology found descent with modification  by 1862. 

Edward Tylor (1871) first started to use culture in the sense meant herein.  Darwin also did cultural transmission.

7 – Veblen did a form of cultural evolution, but it was unsystematic.  And, his sexual scandals may have contributed to the discontinuation of this line of thought.

8 – Spencer’s Social Darwinism was famous.  He said structures progress from simple, undifferentiated homogeneity to complex, differentiated heterogeneity.

It is the second law of thermodynamics backwards.

Bannister’s work is a countercritique of Hofstadter.

 

Julian Steward (1955) critiqued unilinear theories. He noted that small game vegetation hunters were dispersed and large game  folks had more complex social organization. 

9 – Donald Campbell argued that ‘vicarious selectors” might bias learning.

10 – Pinker and Bloom published a landmark paper on the role of natural selection in the emergence of language in 1990.

11- People are now thinking innateness is less important in language acquisition and learning more important.

Cultural evolutionist, specifically, Richerson and Boyd’s dual inheritance theory, has much more room for culture than sociobiology or the pioneers of the descendant fields of human behavioral ecology or evolutionary psychology. 

[They give very short shrift to Ethology; what of Konrad Lorenz].

 

COMMON THEMES ACROSS FOUR AREAS

They are: the structure of human groups, technology and science, language and religion. 

 

12 - He says details of language and religion impact survival less directly than technology and variations in social organization.  I am not sure.

 

Gene-culture.  It is disputed as to which to emphasize.

We’ll see the use of mathematical models.

“Evolution is a population-level process.”  So experiments that seem ethically feasible and logical are too small in scale to be informative.  But, we still use them.

13 – They are simplified caricatures, but they give us insight into real large-scale processes.

Field studies confirm and suggest answers to questions.

14 - As individual level processes ultimately create genetic and cultural inheritance, developmental processes, we look there to determine the gene – cultural balance. For example, how much of Chomsky’s innate mechanism is mediated by culture in language acquisition?

We also look at macroevolutionary events and trends. 

Why did our brain size and cultural sophistication in our lineage increase so over the Pleistocene? 

15 - Why do Holocene societies have boom and bust dynamics?  Gene sequencing is aiding our ability to get useful info out of such questions.  We hope even non-physical items like language and social disposition will find results in the DNA.

 

MAJOR ONGOING PROBLEMS TO SOLVE

Understanding the Epigenetic and Neurobiological systems that underpin culture.

Rizzolatti (2005) investigated mirror neurons as the root of human imitation and culture. 

16 - But, whether to look at the genetic or epigenetic is controversial.  Both? Where is religion?

Proof of gene-culture co-evolution still largely rests on a few famous examples.  More will come.  One method is to look at where genes most vary between populations.

17 – Shennan herein will argue that we think there is substantial cross-cultural variation in social learning strategies.

Since it is new, science as a cultural system is fragile.

We also need to look at differences in use of language in socialization.

18 – REDUCING THE GAPS BETWEEN THE NATURAL SCIENCES, SOCIAL SCIENCES, and HUMANITIES

They argue that the age of the amateur scholar was pre-1890s and the rise of the university led to divisions between disciplines. The 1960s attack on science led to further retrenchment against the social sciences.
19 - The idea was that the biology and evolution are tied to conservative philosophy and so must be shunned.

20 – No one should reject any tools.

 

CONCLUSION

20 – Cultural evolution studies have grown as have those of animal cultures.

They must look at cultural similarities as well as cultural differences.

 

 

PART ONE – STRUCTURE OF HUMAN GROUPS

 

CHAPTER TWO: ZOON POLITICAON: THE EVOLUTIONARY ROOTS OF HUMAN SOCIOPOLITICAL SYSTEMS

By Herbert Gintis and Carel van Shaik

Page 25

 

25 - ABSTRACT

Our primate ancestors evolved a complex sociopolitical order  based on a social dominance hierarchy in multi-male/multi-female groups.  The emergence of bipedalism and cooperative breeding in the hominid line, together with environmental developments which made a diet of meat from large animals fitness enhancing, as well as cultural innovation in the form of fire and cooking, created a niche for hominids in which there was a high return to coordinated, cooperative scavenging or hunting of large mammals. This in turn led to the use of stones and spears as lethal weapons.

 

The availability of lethal weapons in early hominin society undermined the standard social dominance hierarchy of multi-male/ multi-female primates.  The successful sociopolitical structure that replaced the ancestral social dominance hierarchy was a political system in which success depended on the ability of leaders to persuade and motivate.  This system persisted until cultural changes in the Holocene fostered the accumulation of material wealth, through which it became possible once again to sustain a social dominance hierarchy, because elites could not surround themselves with male relatives and paid protectors.

 

This scenario suggests that humans are predisposed to seek dominance when this is not excessively costly, but also to form coalitions to depose pretenders to power.  Much of human political history is the working out of these oppositional forces.

 

SELF_INTEREST AND CULTURAL HEGEMONY MODELS OF POLITICAL POWER

 

Two systems have dominated: self-interest for biology, political science, and economics.  Cultural hegemony ruled sociology, social psychology, and anthropology.

 

26 - People reject cultural mores daily – so the group view has problems. And, people will resist trades in which they get more if they think them unfair – so the individual one has problems.

 

27 – If only self-interested, people would never vote.  It gets them nothing and their vote doesn’t matter. Political opinions are also a waste of time, your spreading them to several people has no impact.

 

But there is also “shared intentionality;” It is a categorical imperative sort of thinking wherein the “we” fulfills duty, it is reflects a pro-social disposition.

 

28 – We are what Aristotle called “zoon politikon” political beings.

 

THE POLITICAL AND ECONOMIC STRUCTURE OF PRIMATE SOCIETIES

 We are one of 200 existing primate species.

Chimp raids have a large group against a small one.  Only humans have two huge groups on either side, with the outcome unknown.

 

Primate groups rarely engage in collective action.

29 – This means they don’t need leaders so much. 

Both sexes create dominance hierarchies, get more food and mates.  Female primates rely more on alliances to get dominance than males.  Displaying towards predators is the only common group benefit dominants confer.

 

Male chimps provide no leadership or parenting. Women are spread so paternity is uncertain.  Men do, though, dispute resolution.

 

The two kinds of male chimp coalitions are dominance ones with a male and another male.  And, ‘leveling coalitions’ that stop the top males from taking too much and harassing subordinates.

 

THE EVOLUTIONARY TRAJECTORY OF PRIMATE SOCIETIES

30 – We branched from other primate 6.5 million years ago.  3.5 years ago still not a true bipedal as the arms were big for climbing. After they got smaller for throwing.  31 – The leg bones got sturdier too.

 

CONTROL OF FIRE: A PRECONDITION FOR SHARING NORMS

We have firm evidence of controlled fire 400,000 years ago in Europe and 800,000 years ago in Israel.   Since most predators have an instinctual fear of fire, having fire meant primates did not have to retreat to trees at night.

 

Fire cooking meant prey was brought back to a central location and sharing and moral order were kick started.   This also meant a short colon, that reduced the time chewing each day from 4 – 7 to 1 hour a day.

 

FROM GATHERER TO SCAVENGER

2.5 MYA (million years ago) Australopithecines branched in two ways. One led to a dead end about 1.4 MYA. Another to us.  Weather probably played a part as several animals had greater encephalization.

 

We were more likely scavenger hunters, who chased the hunters away with weapons.

 

33 –Homo Habilis males weighed under 100 pounds.  They had sharpened tools but likely scavenged, rather than hunted – as some modern chimps and baboons do. 2.5 MYA stone tools expanded.  But, these were likely for throwing and cleaning, not really hunting.  Even those 200,000 years ago show no sign of being for hunting.

 

700,000 years ago we developed the ability to throw.

 

SOCIAL HIERARCHY: DOMINANCE AND REVERSE DOMINANCE

34 – There are immediate-return and delayed return human organization systems.  Delayed return only came into being 10,000 years ago.  This allows storage of boats, beehives, nets, etc.  It also makes social dominance hierarchies such as lineages, clans, and chiefdoms possible.

 

35 - They will call immediate return societies “simple.”  These were extremely egalitarian due to interdependence and the ability to punish.

 

Big game hunting started only 250,000 years ago.  But, current hunter gatherers are violent, competitive, and unequal, though they use morality in sharing big game food.

 

36 - Large game made cooperation pay off.  This required hunting and cooking.

Boehm’s Hierarchy in the forest looks at reverse dominance hierarchy.  This means anti-hierarchical feelings.

 

37 – Woodburn says this reverse dominance hierarchy is a result of lethal weapons, which neutralize coercion.

Boehm says Late Pleistocene Appropriators (hunter gatherers) (LPA) used gossip and collectively policing and informal meetings to collect info on members.

 

The human lifestyle requires, unlike chimps, many collective decisions, like when to move camp.

 

38 – In other primates dominants influence decisions more. And our dominance is based on persuasion and coalitions.

 

ARE THERE EGALITARIAN NONHUMAN PRIMATES?

No

39 – Bonobos have steep dominance and studies vary on whether it is more male or female.

Where there is less dominance there is less paternity certainty. [ISLAM] But, we’re the only multi male / female egalitarian primate society. 

 

PHYLOGENETIC AND CULTURAL IMPLICATIONSOF GOVERNANCE BY CONSENT

 

Making coalitions, post weapons, requires logic, analytical abilities, social cognition, and linguistic facility.   We’ve had such weapons for 2 million years.

40 – As Dunbar noted, this increases group size and cephalization.

 

This demotes Darwin’s [and Geoffrey Miller’s} favorite sexual selection mechanism.

 

COOPERATIVE MOTHERING AND THE EVOLUTION OF PROSOCIALITY

20% or more of primates have allomaternal (shared) child raising.   This could be a result of our weapon produced pro-sociality.

41 – As hominin brain size increased so did long immaturity. We developed intergenerational info transfer.  Our shared intentionality can be traced back to the evolution of cooperative breeding and hunting.

 

LETHAL WEAPONS AND EGALITARIAN ORGANIZATION FROM THE HOLOCENE TO THE PRESENT

With the development of settled trade, ag, and private property a male could gather males around him that would protect him from the revenge of a dominated populace.

 

Aristotle said cavalry creates strong oligarchy.  Infantry creates democracy.  

 

42 - The true hegemony of the foot soldier came about with hand-held weapons.  Before that heavy artillery could pound artillery.  Thus democracies fought each other with machine guns in WW I.

 

CONCLUSION

Herein we see culture gene coevolution.  Also, the sociophychological theory of norms.  Many reject this because it posits a causal social role above that of individual actors.

 

But this individualistic assertion is incorrect because “social norms are an emergent property of human society.”  All attempts to explain human culture without this higher level construct fail.

 

43 – We were in complex societies based on dominance at first.  Enabled by bipedalism, meat and cooking made cooperation rewarding. This, in turn led to the creation and use of weapons.

 

This reorganized the upper torso to maximize throwing and grew neural circuitry that allowed the rapid sequencing of body movements.

 

Along with weapons, two sociopolitical structures arose to help efficiency.  Reverse dominance hierarchy, which made persuasion important.  And cooperative breeding and hunting, which made folks share.

 

This continued until the Holocene brought wealth accumulation.

 

This speaks to our forming coalitions and keeping them to stop pretenders to power.  We also make such coalitions to create power. 

 

There is therefore, no inevitable triumph of liberal democracy over despotic political hierarchies.  Despotism will always challenge.  We seem to be indisposed to social dominance hierarchy unless it is culturally legitimized.  

 

44 - Legitimization only happens in a few ways: patriarchy, popular religion, or liberal democracy.

 

CHAPTER THREE: HUMAN COOPERATION AMONG KIN AND CLOSE ASSOCIATES MAY REQURE ENFORCEMENT OF NORMS BY THIRD PARTIES

- By Sarah Mathew, Robert Body, and Matthijs Van Veelen

- Page 45

ABSTRACT:

While our capacity for large-scale cooperation is striking, humans also cooperate with kin and close associates much more than other vertebrates.  Existing theories do not satisfactorily explain this difference.  Moreover, mechanisms posited for explaining large-scale human cooperation, like norms, third-party judgments and sanctions, also seem to be essential in regulating interactions among kin and close associates.  It is hypothesized that norms and third party judgments are crucial even for small-scale cooperation, and that kin selection and direct reciprocity alone cannot generate the degree of small-scale cooperation needed to sustain the human life history.

 

INTRODUCTION

 

45 – To explain our unique large group sizes, people have looked beyond direct reciprocity and kin selection (mechanisms for small group cooperation): indirect reciprocity, punishment, signaling, genetic and cultural group selection were considered.

 

But if it is kin selection and direct reciprocity, why don’t they work, sans language, with other vertebrates?

 

Enforcement by third parties is key in big and small group cooperation.

 

We cooperate so much and this is key to our life histories of large brains, long life, low mortality, prolonged juvenile period, short inter-birth intervals, and the use of the most nutrient dense plants and animals for eating.

 

OBSERVED LEVELS OF SMALL-SCALE COOPERATION ARE NOT CONSISTENT WITH KIN SELECTION AND DIRECT RECIPROCITY

 

47 – Reciprocity is rare among nonhuman animals.  Grooming is a rare example.

48 – And with breeding cooperation, it is usually subordinates helping with rearing dominants’ kids.

 

People might say that cooperation didn’t evolve in other animals because it wouldn’t pay off in other environmental niches.  But, that doesn’t wash.

 

50 - Kin selection doesn’t explain the difference.

 

The discrepancy is unlikely to be due to cognitive constraints. You can have more cooperative work that is less cognitively taxing.

 

52 – NORMS THAT AFFECT SMALL-SCALE HUMAN COOPERATION

Behavior between kin in humans is subject to norms and third-party enforcement.

Norms regulate many types of cooperation in small scale societies.

Pair bonding is universal and usually has an institutional aspect.

Arranged folks aren’t allowed to choose others and exogamous societies too.

Family and community enforce these. Family even disown their kin over this.

How many you can marry, who pays whom, in-law care, post marital residence, stoning for non-virginity, are all regulated.

Child-rearing too.  Foot binding in China was child-rearing,

 

53 - Pairwise interactions among nonkin are affected by norms and third party interventions.

Between nonkin cooperation is regulated by norms and third parties often intervene to mediate or enforce.

Indirect reciprocity works on reputation.  Direct, fear of defection.

 

In Turkana society a woman must give someone water, unless they violated a norm.  This is regulated by group norms.   So community norms regulate types of cooperation.

If there is a dispute, elders are asked to adjudicate.

 

CULTURALLY EVOLVED NORMS MAY HAVE ENABLED THE EVOLUTION OF SMALL AND LARGE SCALE COOPERATION IN HUMANS

54 – Cultural group selection models have assumed that individuals get normative behavior by copying successful or prevalent behavior, they use the same learning machinery they use to other items. 

However, complex moral behavior might be hard to pick up without innate scaffolding.  Our norms are abstract. We recognize that situations are similar and some are conflictual. 

This means that it is like grammar in structure. [Hmnn] We recognize common causes and conflicts of interest in novel situations in situations that haven’t yet happened. 

55 - With this ability, third party enforcement would be possible.

[But isn’t this like saying if it was already there it would already be there?]

 

If warfare created cooperation, it would be likely to misfire.  But, norms can scale up with no problem.

Cooperation on small-scale groups would depend on cues from family membership. Rooted in individual identity. Should I help?  Bob is my uncle. Famlily’d be the 3rd party.

Cooperation in large-scale groups is via institutions and more likely from cultural group selection.  Cues from group identity. Should I help?  He is an American. Society would be the 3rd party.

 

WHY ARE SOME NORMS NECESSARY TO GET THE BENEFITS OF COOPERATION?

56 – How might the evolution of norms and kin selection or repeated interaction be related?

 

Norms and third party enforcement may resolve problems of errors – which may explain why pair cooperation may not emerge from direct reciprocity.

 

But admittedly, indirect reciprocity is even more prone to error than direct.  Direct is easy to find cheaters.  Indirect, not so much.  And the increase in error detection from indirect, when pairs meet so often, would not be big. 

 

57 – But it would clear up instances when two folks see different levels of reciprocity.  And, social norms would give the 3rd party a basis upon which to judge.

 

Norms can help identify how to get the benefits of cooperation in the local ecology.

 

58 – Without specifics, norm creation could allow practitioners some assurance that following norms will result in some benefit.  But, he says no. So much is done, again, without norms.

 

NORMS AND THIRD PARTY ENFORCEMENT CAN ELIMINATE INEFFICIENCIES CAUSED BY ASYMMETRIC INTERESTS AMONG PAIRS OF INDIVIDUALS

 

58 – In pair bonds, parents and each sibling may have different interests.  Norms can help mediate these.

 

59 – NORMS AND THIRD-PARTY ENFORCEMENT MAY RESOLVE INFORMATION ASYMMETRIES TO INHIBIT THE EVOLUTION OF COOPERATION.

 

If a juvenile tells his mother he can’t go to school or needs more food cause he is sick can cheat and play as soon as she is not looking. But community enforcement stops this.   It cleans up false signals.

 

CHAPTER FOUR: THE PUZZLE OF HUMAN ULTRASOCIALITY: HOW DID LARGE-SCALE COMPLEX SOCIETIES EVOLVE?

 - By Peter Turchin

 - Page 61

 

ABSTRACT:  How we evolved large-scale sociability is usually not looked at.  We look at how we got small-scale sociability.  Theories about how small scale societies evolved have 2 problems: They rely on verbal reasoning.  Second nothing gets compared to data.   This has happened repeatedly around the world. 

 

62 – INTRODUCTION: THE THEORETICAL BACKGROUND

 

With voting, joining the army, paying taxes, we’re looking at a public good.

Ultrasociability is the ability of humans to cooperate with genetically unrelated groups.

 

Usually theories have several steps, cooperation among lower level groups, policing and competition among lower units, risk pooling, economic returns for division of labor, if a place has more warriors or tax payers it wins.  (63) Suppression of inequality is in the mix. Moralistic punishment and culture via conformist transmission reduces in group variability and enhances between group variability.

 

We need bigger brains to keep track of face-to-face interactions.  But even this peaks at 100 people.  How did the next level happen?

The second step, large-scale ultrasociality was enabled by several key adaptations.

a)      The ability to do symbolic markers to demarcate ourselves.   These appeared around 60,000 years ago.  Dialect, cult, religion, clothing etc. 

b)     Hierarchical organization, centralized ones are best in war (causing inequality).

c)      Other innovations include literacy, legal systems, organized religion, and states.

 

64 – Though controversial (and ever less so) cultural evolution is providing a unifying conceptual framework for the political thinkers, anthropologists and social biologists to explain states.  

But these are often verbal, not mathematical.  Math based theories are starting to look at the import of differences between groups, warfare, special charactristics of when groups emerged. 

65 – Experience says we won’t get a theory with only data, we need a model. Then a suite of testable models.

 

FINALLY NOW . . . HE’LL LOOK AT HOW IT HAPPENED

66 - There are lots of different ultrasocial groups: traditing networks, ethnic diasporas, religious cults, etc.  We’ll just focus on the polity: These range from villages to simple and complex chiefdoms to states and empires.   It is unique because it has sovereignty.

 

Ultrasocial norms and institutions

What evolves?  Institutions are systems of culturally acquired rules that govern behavior of individuals in specific contexts.  When individuals internalize aspects of these rules, they’re norms.

 

Norms help adjudicate between individuals and the group.

 

Some benefits only happen with large scale and the costs are born at the bottom.  As such, we expect the benefits and institutions to collapse at lower levels.  We can test this.

 

Examples:  Generalized trust.  Ethnic groups can free ride on this.  Bureaucracies conflict with chief rulers, but they are necessary in larger groups.   Systems of formal education.  Literacy collapses in dark ages show how important these institutions are.   Universalizing relligions first appeared 800 to 200 bce.  They knit the first mega-empires.  But he sees them as prosocial, not just ultrasocial, because moralizing gods are useful to stabilize cooperation even at the village level.

 

70 – An argument can be made that universalizing religions would not be good at the village level because they blur ethnic lines.

 

CULTURAL MULTILEVEL SELECTION AS THE THEORETICAL FRAMEWORK

We need an institutional mechanism that would spread despite costs.

He thinks “cultural group” or “multilevel selection” (Cultural MLS) best illustrate hierarchical organizations because they have different levels of organization that accrued over time.

 

 

 

71 – The MLS question is “What is the balance of forces favoring cooperation of lower-level unites and, therefore, their ability to combine into higher – level collectives?”

 

Herein the cost of adding a level must outweigh the cost. 

 

This math predicts that large states should arise in regions where different people are in contact and where competition, warfare, is intense.   It turns out that over 90 percent of the largest historical empires arose in world regions classified as steppe frontiers.  The prediction is matched.

 

CONCLUSION: War, Peace, and the EVOLUTION OF SOCIAL COMPLEXITY

72 – Failed states are a big problem.  It has resulted in nation building.

But the results have not been impressive.

We need to understand cooperation and war dynamics better.  [But, if you don’t deal with Muhammad and only look for generic dynamics, you’ll not find it.]  He prefers auto-nation building.  [ISIS]? 

 

73 - Should new nations be parliaments or presidential? Confederacy or unitary state? Numerical models are needed.

What factors will allow us to cooperate in large scale structures?

MLS models will help us in nation building and preventing collapse.

 

CHAPTER FIVE: LIKE ME: A HOMOPHILY-BASED ACCOUNT OF HUMAN CULTURE

- By Daniel B. M. Haun and Harriet Over

- Page 75

 

ABSTRACT: This chapter presents a homophily-based account of human social structure and cultural transmission, wherein a tendency to favor similar others (homophily) is a key driving force in creating human – unique forms of culture.  Homophily also accounts for observed striking differences between human groups.  From early in development, evidence demonstrates that humans show a strong tendency to interact with and learn from, individuals who are similar to themselves.  It is proposed that homophilic preferences of the group, in general, creates a feedback loop to ensure that children engage in high-fidelity copying of the group’s behavioral repertoire.  This allows children to reap the benefits of others’ homophilic preferences and so maintain their position within the group.  In consequence, homophilic preferences have transformed a number of mechanisms  which humans share with other species (e.g., emulation and majority-based transmission) into human-unique variants (e.g., social imitation and conformity).  Homophilic preferences have, furthermore, spawned a new tendency to interpret the structure of actions as social signals: norm psychology.  The homophily account thus connects previously disparate findings in comparative, developmental, and social psychology and provides a unified account of the importance of the preference for similar others in species-specific human social behavior.

 

INTRODUCTION

With variation and immigration the stability of cross-group differences is stark.

76 – And newborns not only meet prototypes of the culture, but folks who don’t conform.

How do they do it?  Learning mechanisms like high – fidelity imitation and cognitive abilities like perspective taking.

But, they emphasize social processes, actually, homophily. 

This is based on two claims: 1) Kids prefer to associate and learn from people like them and 2) this means they get the characteristics that are like them.  This makes for high-fidelity copying.

This approach unites research on imitation, group membership and normative behavior.

 

HOMOPHILIC: SOCIAL PREFERENCES FROM AN EVOLUTIONARY PERSPECTIVE

 

Cooperation requires knowing cooperators from defectors.

As groups got larger, several hundred, we couldn’t know all personally.  We needed stand-ins for personal knowledge. Similar phenotypes.

This causes subpopulations to become culturally isolated.  This allows locally adaptive traits to converge to an optimum.

This is different than one based on success, which would only change slowly.

This tendency is stronger in us than other primates.

 

LIKE ME?  HOMOPHILIC SOCIAL PREFERENCES FROM A COPARATIVE PERSPECTIVE

 

78 – Chimps like those in the in-group and don’t like those in the out-group.

Except migrating females, strangers detected in the home-range are killed.

This is likely based on familiarity, not similarity.

 

Capuchin monkeys prefer those who imitate them to those who don’t.

 

6 year olds prefer to look at individuals who speak their own language.  And 10-month-olds prefer toys from those who speak their language.   5 year olds them as friends. But, we cannot tell similarity from just being easier to understand in these studies.

 

79 – But three year olds prefer puppets that look like them.

 

Minimal group formation tests show children prefer their in-group.

 

But, people in different regions rely on different cues:  Children from accent heterogeneous populations rely more strongly on accents as a similarity cue than children from areas with homogenous accents.

 

Children learn more about novel objects from people with their accent at 5.

LIKE ME!  THE CONSEQUENCES OF HOMOPHILIC PREFERENCES

 

80 – Children may not be trying to imitate others, only to improve social relations.

81 – In emulation, we work towards an outcome, not towards imitating.  Chimps emulate, but imitate poorly. 

Children, in contrast, imitate faithfully. They even imitate superfluous actions. They ‘overimitate.’

Beyond practicality, there is a social element to their ‘over-imitation,’ it serves a funtion.

When belonging is important they overestimate more.

82 – 10 year olds over imitate when they want to persuade the other to do something later.

Majority – biased transmission becomes conformity.

Homophilic preferences not only impact individual interactions, but how we respond to the group; we consider the majority.

With no prior info, chimps follow the majority. But, they don’t do so if they must forego what they normally do.  That, is the definition of conformity.  Children do this. 

Even if they are successful at a task, they choose an less successful method if it is popular.

83 – Children make their actions conform more if the actions are public and less if private.

 

THE EMERGENCE OF NORM PSYCHOLOGY

Chimps have norms in that they have subordinate actions that are stereotypical. But these are not learned, they are similar across populations.

Chimps do not punish other’s faux paus, the dominant does it.

We even enforce behaviors we’re not a part of.

Children pick up norms without direct instruction.

Following a single demonstration by adults, children do it that way and enforce deviations. They use normative language in their protests.

 

CONCLUSION

This may be a key factor in explaining human cultural transmission. 

 

[They assiduously avoid race and ignore Rushton, though they undoubtedly know his work]. 

 

 

 

 

 

 

 

 

 

CHAPTER SIX: CULTURAL EVOLUTION OF THE STRUCTURE OF HUMAN GROUPS

By Fiona M. Jordan (FJ), Carel van Schaik (CS), Pieter Francois (PF), Herbert Gintis (HG), Daniel Haun (DH), Daniel Hruschka (DH), Marco Janssen (MJ), James Kitts (JK), Laurent Lehmann (LL), Sarah Mathew (SM), Peter Richerson (PR), Peter Turchin (PT) and Polly Wiessner (PW).

Page 87

 

This section will look at what made the leap from small (hundreds to thousands) to huge societies possible?

 

MECHANISMS ENABLING COOPERATION IN HUMAN SMALL – SCALE SOCIETIES

 

88 – Primate groups contain many non-relatives, so kin theory doesn’t explain their cooperation very well.   Familiarity could be an extension to kin.

89 – Most mobile hunters-gatherers live in bands of 15 – 50 people, but they regularly interact with 6 – 10 nearby bands.  Sometimes folks even talk outside the nearby band via, cousin of your spouse type connections.

90 – Mechanisms that allow cooperation in our last common ancestor (LCA) with primates:

Kin recognition;   respect of territory mates;    structured interaction;     “reverse dominance hierarchy;”       Direct reciprocity;    coalition formation;       multilocal residence;    cooperative breeding;       marriage;       multilocal ties outside the group;   moralistic punishment;    Reputation and gossip;     leadership by persuasion;    Norm psychology;     Lethal force at a distance;     Language;    Symbolic ethnic markers;    cultural boundaries disposition;       predisposition for cultural rituals.   

 

These go from shared with LCA to not shared.  Norm psych on is not in LCA.

 

91 -  The first emphasis is on similarity leading to norm psychology; be the same to not be punished.   We have a natural tendency to categorize.

 

92 – For markers of ethnic distinction to be stable, they must be socially costly, permanent or both.

 

These markers require niche parameters such as : 1) fixed location; 2) controlled us of fire for cooking or defense; 3) hunting or scavenging; 4) Resource pooling; 5) Savannah living (which requires group defense against predators); Environmental change.

 

Prior to the control of fire (500 – 300,000) years ago, we went into the trees at night.  This would have allowed a social life at night.   Cooking and a central location may have led to sharing norms.

 

94 – CONDITIONS FOR THE EVOLUTION OF COOPERATION IN SMALL – SCALE SOCIETIES

 

3 preconditions:  1)  Increasing returns to scale with group size;  2) control of defectors;   3) cultural group selection / assortativity.

 

1)     the benefits of size in hunting level off pretty quickly.  The most convincing suggestion they make is that group size helped in warfare.  Though I also like size having an impact of “the sophistication of the culture that can arise and be maintained.”  And we must know how to stop people from free riding such benefits.

2)     Control of defectors can happen by group selection: groups that have more cooperators will do better. Adding mechanisms like moralistic punishment also helps.

3)     (96) Social norms and institutions being monitored and enforced are a prerequisite for long – lasting communities.  To be successful, the rules must be well understood and accepted.  They are learned from childhood.  Norms can also be anti social.

Societies run by norms called institutions; marriage, trade and finance, armies.

97 – We do not leave marriage to kin selection and reciprocity, we have cultural institutions to mold it.

 

Norm regulation; internalization, rewards, and punishment

 

97 – Punishment is costly if it costs a productive person.  Promoting a good person is better.  Gossip, shaming, and withholding assistance are other methods.

 

98 – Is ‘respect for authority’ an evolved characteristic?  [Aren’t they all?]

 

Assortivity means cooperators must hang out with cooperators for max benefit. Adopting the trait most have will sort into cooperators and non-cooperators.

 

Also:

1.       Interaction partners tend to resemble each other.

2.       Partners of partners tend to also be partners.  This is transitivity or triad closure.

People can see this cooperative triad, so norms grow.

 

Small-scale society cooperation in human evolution: Inspiration from Darwin.

Darwin noted that groups with more sympathy and patriotism would outcompete others. 

 

100 – Modernized Selection, - either directly on genetic variation (Bowles and Gintis) or indirectly via culturally mediated social selection on genes within groups (Richerson and Boyd 2005) – remodeled ape/hominid social psych to be much more prosocial during the Pleistocene. 

 

Cooperation:

Cooperative breeding has been hypothesized to be foundational for the evolution of small-scale societies. 

 

We are not independent or grown for a long time.  But, our interval between kids is shorter than for other primates.  This would not be possible without the help of pre and post reproductive women and men chipping in. This allows for robust population growth rates.   This also fueled our “other regarding impulses” (Hrdy). 

 

101 - Tennie says our cooperation just comes from the stag hunt.  But cowards and deserters are a problem even in pre-state raiding. 

 

EVOUTIONARY PROCESSES RELEVANT TO UNDERSTANDING HUMAN SOCIALITY

Types of learning and engines of change

102 – There is individual and social learning.

Different combinations of these will have different payoffs for individuals.  This can change within a lifespan.  This process is driven by 1) cultural group selection and 2) endogenous social change.

 

- Cultural group selection -

 

“Cultural group selection refers to a competitive advantage for a group as a whole that arises from within-group norms, practices, etc.,

 

Between group genetic group selection wouldn’t work.  Cultural would.

 

103 – Empirical support includes group functional behaviors spreading through cultural group selection in New Guinea over a few hundred years. 

 

Mathew and Boyd (2011) found norms governing warfare among Turkana pastorilists in East Africa generate group-beneficial outcomes. 

 

Competition methods between cultural groups:

Warfare, population growth, immigration, adopting the social institutions of successful groups (ie the spread of democracy).

 

-           Endogenous Cultural Change –

Cultural change can also rise from with-in group processes that generate variation. 

This can come from pro-social forces such as preferences for fair outcomes.  Persuasion from leaders can spread this. Democracies and juries may come from this.   But, these must help in the long-run to survive.

But in the short term, these may escape inter-group selection.

Anthropologists study this diversity.  Biases may limit the amount of possible variation. 

 

-           Genetic and cultural coevolutionary circuits –

 

104 – Cultural mechanisms, including memes, traits, norms, and institutions, may feedback and change genes.

 

Endogenous change would be slower and have more variety.  Cultural group selection would, if successful, promote similar tendencies.

 

SOCIAL COMPLEXITY: WHAT IS THE “PHENOTYPE” OF LARGE-SCALE SOCIETIES?

 

“Social complexity” has been difficult to define for a long time. 

105 – They want to revise it with a multivariate approach.

They start with population size and then measure nestled institutions and their hierarchy and then economic specialization.

 

Large-scale societies support more and different types of information, especially cultural information.  [PLOTINIAN ETHICS]

 

Much of this is in “stored” culture like art,  and literature.  Some in monumental culture, like buildings and public spaces. 

Large complex societies also have religion or religious practices than may have helped cause the large-scale sociality.  They have management technologies like tribute, taxation, infrastructure and weapons.

 

The dark side of social complexity includes inequality. 

 

And it has been argued that the complexity of the large-scale system itself can lead to collapse.

 

TRANSITION FROM SMALL-SCALE SOCIETIES TO LARGE-SCALE SOCIETIES

 

107 – Theories of what drives the transition from small to large include: a) warfare, b) economic efficiency c) information processing capacity and d) demographic diversity. 

 

Sociodemographic clustering means increasing the size and diversity of a population, subject to mixing dynamics) leads to greater cultural homogeneity (Goodreau, 2009). This happens in local neighborhoods within the polis.  Thus this homogeneity in neighborhoods may lead to tension at a higher level.  [diversity is bad].

 

Psychologically, the transition to large-scale requires a) religion and / or b) respect for authority.

 

110 – Respect for authority does not seem to be universal in tribes.  It is more so in large-scale and armies that use prestige rather than coercion are more successful.

 

Religion and tech spread are considered elsewhere.  Here they will look at homogenization, incorporation and management technologies in large scale societies.

 

Sometimes homogenization like Greece is available.  Sometimes, they must incorporate subgroups like Rome and African imperialism.

 

111 - Homophilia, fear of aversion, religion, and a common enemy help with fictive kinship.

 

Engineered roads, trade and fast military deployment are technologies of coordination.

 

112 – surplus storage and redistribution is important. And, some of it can be used to “do culture” ie rituals and spaces that knit the nation.

 

But at what size do each of these infrastructure pieces become necessary?

 

CASE STUDY: ENGA OF NEW GUINEA

350 years ago the south American sweet potato came and they transitioned from hunter-gatherer to horticulturists.

113 – They channeled surplus into exchange ceremonies.

Ancestor and bachelor cults and big men were instituted, as long as war and reconciliation mechanisms.

 

CULTURAL MESOEVOLUTION: BRIDGING INDIVIDUALS, POPULATIONS, and REGIONS

We need case studies, not abstractsion and the use of biological, social, historical and behavioral sciences. 

 

[While understanding the underpinnings of historical transitions to large-scale society is interesting, I would rather see what mechanisms are successful today and then deploy them in an experimental manner].

 

PART TWO – TECHNOLOGY AND SCIENCE

 

CHAPTER SEVEN: THE CULTURAL EVOLUTION OF TECHNOLOGY: FACTS AND THEORIES

- By Robert Boyd, Peter Richerson and Joseph Henrich

- Page 119

 

ABSTRACT:

Until recently, human artifacts were not obviously more complex than those made by organisms that lack cultural learning and have limited cognitive capacities.  However , cultural evolution creates adaptive tools much more rapidly than genetic evolution creates morphological adaptations.  Human tools are finely adapted to local conditions, a fact that seems to preclude explanations of cultural adaptation based on innate cognitive attractors.  Theoretical work indicates that culture can lead to cumulative adaptation in a number of different ways.  There are many important unsolved problems regarding the cultural evolution of technology.  We do not know how accurate cultural learning is in the wild, what maintains cultural continuity through time, or whether cultural adaptation typically requires the cultural transmission of causal understandings.

 

120 – This chapter will look at fact and theory in the hopes of showing that technological spread is evolutionary: they aggregate complexity over time.

This happens as features evolve in biology, but in culture it is much faster.

 

STYLIZED FACTS ABOUT THE CULTURAL EVOLUTION OF TECHNOLOGY

People in the simplest human societies depend on tools that are beyond the inventive capacity of individuals

121 – Clothing, shelter, boats, cooking sans wood, were all part of the inuit technology. All very complicated.   European explorers stranded in unfamiliar areas often starved despite being well educated.

122 – Tool design optimization is very complex and requires much refinement.  They profile the evolution of the axe and that of the rudder.

124 – Genetic evolution leads to complex, adaptive artificats often constructed by animals with simple, or no, nervous system.

125 – Nests, termite mounts, spider webs, and beaver damns, for example.

126 - Single-celled amoeba build homes out of small grains of sand.

127 – Tech now evolves so fast! The quickest genome adaptation known is lactase tolerance that is 5,000 years old.

Holocene era North American Native Americans evolved technology quickly.

128 – Sometimes natural selection seems a tautology: how do we know a gene helped adaptation?  It spread. 

A recessive gene causing blindness spread because the ruling family survived a typhoon and procreated lots. But, adaptiveness is generally true.  In tech designs too. Those that rock drill the cock.

130 – Versions of bows are well designed for their environment.

132 – There may be innate mental mechanisms, some argue, that bias the evolution of technologies. We, for example, prefer straight lines. So it may be easier to invent some kinds of tools and harder to invent others. But the authors doubt it.

 

THEORY RELEVANT TO THE CULTURAL EVOLUTION OF TECHNOLOGY

133 – One strategy for tech evolution is some innovate, most imitate the successful.

134 – Cultural learning allows folks to learn selectively.

135 – Evolution would produce an ideal blend of innovation and imitation for a population to remain stable and still compete.  This is shaped by the fact that learning new behaviors is hard.  So, huge changes are not likely to spread.  But small adjustments can.

137 – gradual cumulative adaptation can arise from payoff-based transmission

If your uncle’s bow shoots farther and has three differences from yours, and you copy all three, and only one matters, two are free riders.

If we copy from prestigious folks, the best design should filter through.

 

Infants copy from knowledgeable adults, rather than their mothers, in novel situations.

 

138 – The vision of innovation wherein some innovate and others copy gives the cost to the inventor and no benefits.

Market effects of selling the innovation cannot explain early innovation.

 

Food taboos against toxic foods for pregnant women spread without people understanding them.  So not all is rational choice.

 

139 – Some think the prestige and success a new designer gets is a reward.  This seems odd in one life.

 

Large populations have more diversity and so should have more tinkering.   If someone invents a better bow but is a terrible shot, that technology will die.  Loss also happens because students don’t learn new models well. But large communities will have more experts and good learners.

 

Small isolated communities, Tasmania for example, have lost tools. 

 

140 – Kline and Boyd found a positive correlation between community size and number of tools in 2010.  Contact also helped, but this was only marginally important in the island communities they studied.

 

CONCLUSION

141- People don’t invent tools, they evolve.

Genetic transmission is incredibly accurate, and selection is usually weak.

 

And some argue that cultural heredity is so inaccurate that not much can be inherited at the population level (this volume disagrees).  But, frequency-dependent processes like conformist transmission preserves between-group variation and allows cultural transmission.

 

Also, we don’t know how much people understand the technologies upon which they rely.

 

142 - One group says that innovation spreads fast because folks understand innovations and adopt rapidly.

 

Others say no understanding, just prestige bias.   Intermediate combinations are also possible.

 

CHAPTER EIGHT:  LONG-TERM TRAJECTORIES OF TECHNOLOGICAL CHANGE

- By Stephen Shennan

- Page 143

 

One of the benefits of taking a cultural evolutionary approach is that it goes beyond relatively simple ideas of competition and technological improvement, and introduces a range of other forces whose impact is not often considered.  In the case of technology, the entities that are the subject of variation, inheritance, and selection processes are technological lineages, recipes for techniques, routines, and practices linked by ancestor-descendant relationships.  To understand them, we must first address histories of the technologies themselves before we can examine the histories of the human populations through which they are transmitted, which may depend at least partly on the histories of technologies.  A number of examples of technological innovation and transmission are examined to illustrate the variety of factors affecting them.

 

145 – We look at memes and cultural evolution from an agent-centered perspective.  But, the meme must have a relationship to a people and their spread. 

 

And, we wonder, again, if people who use a technology thrive and so the tech spreads OR if the people observe that something is better so it spreads.  Did people adopt farming?  Or did they drive out the folks who didn’t?

 

We must look at the spread of technology and the folks who use it.

 

146 – Some technologies are so basic, they have been invented over and over. Some innovations are uncommon big leaps and so they are hard to promulgate.

 

147 – The pottery wheel appeared, lasted for 1000s of years, reappeared and disappeared again before finding a permanent foothold in middle east culture. 

 

148 – This is because only small elite groups used it.  If it takes a lot of work to learn something, when you could be learning something else, a technology will be that of specialists. And, people want to protect their guild, so this keeps technology groups insular and small.

 

151 – Necessity seems to not be the mother of invention.  When populations collapse, technology recedes.

 

153 – Sometimes innovations lead to a selective advantage and those who use them breed and spread. 

 

[Culture itself was the biggest innovation.  Children absorb culture.  This allows survival more than the stone tool.  That is a side benefit.] This is shown in that technology, well copied, barely changed for 2.5 million years.  

 

154 – Even if something is favorable, having a small population, costs of learning, meaning few to continue the complex art, make it unlikely that the item will spread.

 

People use a ‘ratchet’ metaphor.  But, the move towards complexity does not only go up.

 

 

CHAPTER NINE: NEUROSCIENCE OF TECHNOLOGY

By Dietrich Stout

Page 157

 

ABSTRACT:

Although there is a burgeoning of neuroscience of tool use, there is nothing that might be properly be called a neuroscience of technology.  This review aims to sketch the outlines of such a subject area and its relevance to the study of cultural evolution. Technology definitions may be better understood with reference to neuroscience research on perceptual-motor control, object manipulation, motor resonance, imitation learning, and goal-directed action.  Such considerations suggest a number of biases which may affect the cultural evolution of technologies.

 

158 – Is music a technology? What of complex foraging techniques that don’t use tools?  It is not always clear what to include as tech.

 

Tech a) often involves the use and modification of objects b) is characterized by complexity organized goals and structures, and c) is heavily reliant on social mechanisms for its reproduction.

 

161 – How do culturally constructed objects, situations, and social interactions come to constrain individual behavior?

 

162 – Macaques see tools as extension of their bodies, after long training.  But, this may not extend to humans use of knives and such.  Brain scans will tell.

 

The integration of novel tool use is made possible by the inferior parietal lobe.  This region also responds to seeing tool use.  This is adjacent to where the hand motion part of the motor cortex in monkeys. 

 

The author is focused on how tools constrain human actions.  We must anticipate weight and direction of objects we use.

 

165 – Mirror neurons or some such brain mechanism must be involved in imitation.  This coordinated with the parietal.  These must be integrated with goals.  So we have a multileveled processing.

 

168 – “object can refer to a thing or a goal.”  There are high-level constraints too.

When market forces were introduced, blankets became more complex in one Indian region.

171 – Structured Event Complexes are SECs.  It is “a goal-oriented set of events that is structured in sequence and represents features, social norms, ethical and moral rules, and temporal event boundaries.  Walking into a restaurant will set off  such a complex.   It is like the priming of semantic concepts. 

 

Such physical and mental limits and tendencies must impact invention.  It is not all disembodied goal oriented vision.

 

CHAPTER TEN: SCIENTIFIC METHOD AS CULTURAL INNOVATION

 - By Robert N. McCauley

 - Page 175

 

175 – We are downplaying the role of culture in scientific inquiry.

 

176 – To see this we must clarify how much science does or does not naturally come to human minds.  He starts by looking skeptically at the scientific method.  He must situate the positions that a) construe science as the outcome of natural predilections of the mind, emphasizing its continuity with commonsense and b) fixate on the inevitable entanglement of science with technology.

 

a) takes insufficient notice of the elaborate measures necessary to insure critical scrutiny and the large investment in education needed.   And b) minimizes the vital position that cognitive ideals occupy.

 

He’ll use history to show the fragility of this enterprise.

 

Kuhn and Feyerabend have assailed science as a rational enterprise.

 

177 – Robin Dunbar says people plan and live via hypotheses so that science comes as naturally to many animals as it does to humans.

 

178 - Some explain science as an organizing principle like religion.  But all such folks have overplayed their hand.   All attempts at coherence in the world are not science.

 

179 – To Dunbar, Michael Tomasello says chimps do not understand explanatory science.  They don’t know why.

 

What distinguishes science is a fixation on criticism, systematically recording evidence, and generating new evidence, and assess that evidence.

 

Technology can happen without science (axe).  But once it met science it really took off.

 

182 – Technology has been in every culture.  But science is rare.

 

183 – Two dozen other cultures use technology.  Only we do science.

 

Science may have come from practical needs.  Ancient societies collected star data for calendars.  But, the Greeks were the first to compare theories as theories.  By this definition, the Chinese never sustained a tradition of science.

 

185 – We are poor at rational thought by some tests.

 

187 – Science does not depend on the insights of one human, but many running confirmation.  That science arose in the first literate cultures is not an accident. Written symbols let us store ideas.  You need a community of scientists to do it.  Peer review  and replication are integral to it.  Scientific work must be available.  Universities help with this as do scientific societies.

 

189 - “State-supported institutionalized experimental science arose in the ninth and tenth centuries in Baghdad and persisted for two centuries in a few locals in the Islamic world.  Medieval Arabic science, however, never enjoyed a lasting alliance with educational institutions independent of Islam, which has generally proven less congenial then Christianity to scientific education.  Without political cover from local rulers, scientific institutions had short lives.”

 

190 – Modern science requires a vast infrastructure.

 

Science is rare and fragile.

 

CHAPTER ELEVEN: THE CULTURAL EVOLUTION OF TECHNOLOGY AND SCIENCE

- By Alex Mesoudi (AM), Keven Laland (KL), Robert Boyd (RB), Brigs Buchanan (BB), Emma Flynn (EF), Robert McCauley (RM), Jurgen Renn (JR), Victoria Reyes-Garcia (VRG), Stephan Shennan (SS), Dietrich Stout (DT) and Claudio Tennie (CT).

- Page 193

 

ABSTRACT:

Both technology and science are prime examples of cumulative cultural evolution.  A key benefit of an evolutionary approach to technological or scientific change is “population thinking,” where broad trends and patterns are explained in terms of individual-level mechanisms of variation, selection, and transmission.   This chapter outlines some of these mechanisms and their implications for technological change, including sources of innovation, types of social learning, facilatory developmental factors, and cultural transmission mechanisms.  The role of external representations and human-constructed environments in technological evolution are explored, and factors examined which determine the varying rates of technological change over time: from intrinsic characteristics of single technological traits, such as efficiency or manufacturing costs, to larger social and population-level factors, such as population size or social institutions.  Science can be viewed both as a product of cultural evolution as well as a form of cultural evolution in its own right..  Science and technology constitute separate yet interacting evolutionary processes.  Outstanding issues and avenues for future investigation are highlighted.

 

Our aim in this chapter is to explore how the methods and concepts developed in the field of cultural evolution can be applied to the domains of technology and science.

 

195 – Chimp technology has no descent with modification.

 

Technology uses external means to solve problems.  Is shared knowledge and the process for generating it.

 

198 – Sources of innovation are absent in the non-human world.  Within the field of cultural evolution, innovation has generally been thought of as the functional equivalent to mutation in biological evolution.  Door hinges were likely used in early rudders. Copying errors. Mutation and copying must have selective copying for advances.

 

199 – Types of social learning, from one individual to another, is rare in non-human species.  For tech to spread, fidelity in copying must be maintained.  Imitation and teaching do this well.  Tech requires teaching.   Young humans and adults over copy. 

 

200 - Facilitatory developmental factors are also rare outside of humans.  We imitate and learn and have the capacity to do so.  We have structures to facilitate learning.  This leads to cultural intelligence.

 

201 – Cultural transmission processes are outside of humans.  This includes who copies whom. There is also a conformist bias. We have guided variation.  If folks guide their variation in the same way, we have directional change; guided variation.   This does not work like selection and so is not dependent on the amount of variation in a culture.

 

202 – The Price equation measures cultural change, including tech. 

 

204 – EXTERNAL REPRESNTATIONS AND HUMAN-CONSTRUCTED ENVIRONMENTS

 

205 – Artifacts themselves are a medium of cultural transmission.  We can follow their spread and longevity like that of species.

 

Writing is the most prominent external representation.  It too evolved culturally. 

 

207 – Niche construction theory (NCT) looks at the cultural and material necessities to continue culture and technology, including animals herded and plants domesticated.


RATES OF TECHNOLOGICAL EVOLUTION

What are the unites of cultural evolution?  A) knowledge, b) behavior, c) artifacts = a) gene, b) phenotype and c) extended phenotype. 

210- The Price equation looks at this as do other models.

The fitness landscape contributes to speeding up or halting the spread of innovation.

 

SCIENCE

It is a recent cultural innovation. 

It evolves historically.

It became its own driving force when it institutionalized itself.  

The future must take the isolation of science into account. Individuals cannot do it, it requires institutions.  The quantitative measure of science is called “scientometrics.”

 

213 – The average Nobel science recipient has gone from 32 to 38 due to the extra time now needed in training.

 

Eventually people will spend so much time learning what has been learned they won’t have time to innovate.  Specialization helps with this.   People worry this will cause group think, though.

 

CONCLUSIONS

214 - The methodological toolkit and theoretical framework are now in place to study the evolution of science.  Empirical case studies can now begin.

 

In future, they hope to link to economic models of the evolution of institutions.  Economists have looked at the evolution of institutions governing international trade in the Renaissance. 

 

215 - Also, how much change depends on rational causal understanding of problems? Ethnological and archeological evidence suggests people rarely know why a technology works.

 

And how fragile is science?

 

216 - Can we vaguely predict the evolution of technology?  This info could also help by stopping the spread of harmful technologies.  Marketers and folks have looked at the emotional salience of a technology.

 

But, science itself gives reason not to jump straight to applications.  Pure science will give a better read.

 

 

PART THREE – LANGUAGE

 

CHAPTER TWELVE: THE INTERPLAY OF GENETIC AND CULTURAL FACTORS IN ONGOING LANGUAGE EVOLUTION

- By Stephen Levinson and Dan Dediu

- Page 219

 

ABSTRACT: This chapter discusses recent advances in our understanding of the complex interplay between cultural and biological factors in language change and evolution.  Three “myths” (the independence of biological and cultural evolution, a fixed biological foundation for culture, and the cognitive uniformity of humans) are identified and falsified.  Strong genetic biases are shown to affect language profoundly, using the example of village sign languages that emerge and complexify due to persistent high frequencies of genetic deafness in certain communities.  Evidence is presented for the genetic bases of language and speech, and the extensive genetic variation within populations affecting them.  Finally, it is proposed that in addition to intrapopulation variation, interpopulation differences in genetic biases that effect language and speech contribute to the emergence of linguistic diversity, through iterated cultural transmission across generations as well as communication and alignment within them.  Thus, biological and cultural processes cannot be meaningfully separated when studying the cultural evolution of language.

 

CULTURAL EVOLUTION AND BIOLOGICAL EVOLUTION ARE TWO SIDES OF ONE PROCESS

 

220 - This chapter says:

1.       Cultural and genetic evolution constitute twin tracks of an evolutionary process.

2.       There are two-way feedback relations between the tracks.

3.       These relations are ongoing.

4.       There is significant variation within populations both with regard to genes and cultural variants, which supplies the “fuel” for evolutionary processes.

5.       Even slight differences in the distribution of gene frequencies within populations can bias vertical and horizontal processes and thus seed cultural evolution.

 

In regards to # 2, different timescales of cultural and biological evolution is not an impediment to co-evolution.  In addition to lactose tolerance spreading, he mentions the adaption of the immune system to the diseases we have brought upon ourselves by migration, farming, behavior, sexual mores or misuse of antibiotics.

 

222 – In villages with deaf people, wherein people all learn sign language, deaf and non-deaf marriages are common.  This increases the amount of deafness in the community. 

 

223 – This also shows that it takes 6 – 10 generations for highly structured artificial languages to evolve de novo.

 

Page 225 –

 

THE FUEL OF EVOLUTION: GENETIC VARIATION IN THE POPULATION AS EVIDENCED in LANGUAGE PERFORMANCE

 

There is a fiction in the humanities that human evolution is somehow in abeyance.

 

Some disorders, such as stuttering, language impairment, and dyslexia show language are heritable.   226 – Normal variations in language such as vocabulary size and second language learning seem to also be genetic.   We see this in the size of the hard palate, tongue size and acoustic properties of speech, such as vocal tract and physiology.

 

FOXPS is a source of research on this topic.

 

227 – Linguistic and genetic spread does not seem to track as well as we had hoped.  But we’re working on it.  And, he reminds us, 85 – 90 % of genetic variations are within groups. Only 10 – 15% happens between groups.

 

LANGAUGE DIVERSITY SEEDED BY GENETIC DIVERSITY

1.       Genetic diversity within populations harbors a range of potentially culturally reinforceable language phenotypes.

2.       Small genetic differences between populations may slightly bias cultural transmission and so tip cultural evolution in particular directions.

Just as there are gifted singers and non-gifted singers in populations, diversity happens.

 

229 – Consider some tones have contrastive tone on words and some do not.  Chinese speakers show greater language in the right hemisphere, due to faster processing speed there.

 

230 – Alleles, via bias, will spread through an entire population till they’re fixed.   Palate shapes facilitate certain vowels.  Populations have different palate shapes.

 

CHAPTER THIRTEEN: LANGUAGE DIVERSITY AS A RESOURCE FOR UNDERSTANDING CULTURAL EVOLUTION

By Nicholas Evans

Page 233

ABSTRACT:

This chapter outlines the various ways coevolutionary models can be applied to language change, and durveys the many ways diversity manifests itself both in language structure and in the organization of diversity beyond the language unit.  Problems of establishing comparability and characterizing the full dimensions of the design space are discussed, including the distribution of characters across it, the correlations between them, and the challenge pf establishing diachronic typologies (i.e., establishing the likelihood of different types of transition, including the insights that could be reached through properly focused studies of micro-variation). It concludes by surveying the main types of selection that mold the emergence of linguistic diversity – psychological / physiological, system/semiotic, and genetic/epidemiological – and spells out seven major challenges that confront further studies of linguistic diversity within an evolutionary framework.

 

 

234 - Structuralists discussed each language on its own term.  Chomsky saw generative processes as universal.  So, neither looked at evolution.

 

235 – Languages are structures of a 3rd kind. They are not just straightforward biology, like the kangaroo hop.  Nor the result of intentional human planning like suspension bridges or constitutions.  They are the unintentional outcome of intentional behavior.

 

Biology – culture coevolution: Our larynx, tongue, and ear are the way they are due to language.

 

Social-psychological coevolution: All people speak imperfectly and certain variations take and some don’t.

236 – Chomsky looked at language learning as individually generated. Saussure saw it as out there and deposited in the individual.  Both are abstract models.  Individuals and the group’s language interact. As does social reality and biology.

 

Language has evolved to be learnable.

 

Culture – Language  - cognition coevolution:

 237 – There are two theories of variation herein. 

The weak Sapir Whorf says that language has some impact on cultures’ thought. We see what our language has us look for. These studies have been on individuals.

 

The Vico-Herder is an “ethnosyntactic” phenomenon, wherein some cultural preoccupation ends up shaping the grammar.  There are many examples, but it is hard to measure.

 

There are also social scale phenomenon wherein language changes due to many older immigrants.

 

DIVERSITY IN LANGUAGE STRUCTURE

239 – Signs are not as arbitrary as people thought.   There are many onomatiopoeic words.  Sounds follow combos that are easy to say / hear, and vice versa. In Japanese all verbs end in u or ru.  These are verb markers and so structurally chosen.

 

And the words about knowing are all clustered around each other and build on the same word. Know, knowing, I am knowledgeable about that.

 

242 – Tone langauges are limited in the same way as a symphony cannot just be any sorts of sounds, rules apply.

 

Sociolinguistic variability within speech communities:

243 - How far can a language degrade and change before it is no longer a medium of exchange.  Languages have proven to be very resilient against corruption.  Rather than degradation, the matter is additions of accent and terms for social – signaling purposes such as region, class, caste, religion and so on. 

244 – People do “correspondence mimicry” wherein people consciously try to fit in.

Writing means people can have different spoken languages and be united by the common writing: ala the Chinese.

 

There are also things like Latin that spanned the multilingual Roman empire.

 

245 - Some people speak half of two languages and really neither.

 

246 – There are geographic and social variants.

 

Phylogenetic and typological diversity:

248 – Big mystery: Why does Australia have one language when New Guinea has so many. 

 

251 – Language comparison is hard as we could say 6 languages all have a P sound, only one, or three do, depending on how we categorize.

 

253 – The big problem is there is no ‘design space’ or language categories by which we may classify languages.

 

259  - Three promising areas are 1) word order universals; 2) semantic universals, such as all having a word for orange.  3) phonological universals- how many does a language have?

 

261 – Another challenge is that we only know how several languages have changed historically.

 

Usually, we know, categorical change is preceded by variation.

 

262 – Does natural selection prefer some language systems above others – all else being equal?

 

In New Guinea, we have ‘esoterogeny’ the elaboration of differences. The expensive option may happen due to the need to signal affiliation from childhood.

 

265 – “Kintax” is when language is changed by different kin patterns.

 

265 – Boas’ blank slate model was hurt by Dediu and Ladd in 2007 showing that tonal phonemes correlate with genes that discriminate pitch discrimination.  Lip and palate configurations are not showing up too.

 

CHAPTER FOURTEEN: LANGAUGE ACQUISITION AS A CULTURAL PROCESS

- By Elena Lieven

- Page 269

 

ABSTRACT:

It is possible to identify three elements involved in the phylogenetic and ontogenetic development of the human language ability: a) specific speech-related abilities, b) cognitive abilities related to signification, symbol manipulation, and  categorization, and c) communicative or interactive abilities.  This chapter suggests that although all three elements have a universal basis in evolution and development, they are affected at a rapid pace by the culture within which the infant develops.  During the first year of life infants become increasingly sensitive to the particularities of the ambient language(s).  Their babbling shows both the restrictions on the vocal production caused by the slow maturation of the speech apparatus and the influence of the language they are hearing. By 12 months of age, potentially primate-wide discriminations between types of events have given way to categorizations that reflect those of the language that the child is learning.  Despite differences across cultures in both the ideologies and practices of child rearing, the onset of shared intentionality occurs at around nine months of age and does not seem to be affected by cultural differences in ways of interacting with babies.  Once infants start to comprehend and produce language, there is a great deal of evidence, mainly from research in modern industrial cultures, that language development is influenced by quantitative and qualitative aspects of the ways in which children are spoken to.  The chapter concludes with questions concerning the role of language in socialization and the relationship between concepts of socialization and culture.

 

269  - 270 Language is learned at the same rate by kids everywhere, but language is so different and so input is necessary.  And, attitudes about language vary by culture.  So, how much is innate or absorbed?

 

CULTURAL DIFFERENCES IN COMMUNICATIVE INTERACTION WITH INFANTS

271 – Child rearing always includes body contact, body stimulation, object stimulation and face-to-face contexts.  But very different ideologies stick to these.   In one study of several cultures, Keller (2007) came up with autonomous and interdependent styles.  Interdependent is largely rural and small village, pre-industrial.  In the autonomous, the baby is treated as an autonomous agent, with its own needs and thoughts to be discovered.

 

DEVELOPING LINGUISTIC SENSITIVITY TO AMBIENT LANGUAGE

272 – Many reactions to words, categories, etc are found in infants.  By 11 to 12 months, they can discriminate sounds that are related to their own language.

 

273 – Categorical perception has been shown for some species of monkeys.  But we have something more.

 

Three approaches to what underpins the development of meaning and structure:

1)     Specifically linguistic modularity.

2)     Cognitive capacities that involve higher-order operations with symbols and

3)     Sociocognitive capacities.

 

For the first, evidence suggests, is the outcome of language development, not its cause. The structure to speak came out of efforts to speak.   

Sociocognitive skills start around the ninth month.

 

SOCIOCOGNITIVE DEVELOPMENT ACROSS CULTURES

 

274 - Shared intentionality is not just in humans.   8 – 9 month old infants have triadic joint attention where they look where others are looking; and they express understanding at the shared experience.

 

In rural India and Peru this attentional triad happened at the same time.

 

275 - But Canadian children produced language three months earlier.  Pointing happens at the same time in all cultures.  Words can be learned based on what is pointed at or at least the idea of things, even when ideas.

 

LEARNING THE MEANINGS ENCODED BY LANGUAGE

276 – Children seem to learn categories, like biological versus inanimate at the same rate.  But they learn language categories in ways related to the language they are learning, not universally.  Expacial distinctions are made by their language. 

 

278 – Supplementing Canadians speaking 3 months earlier than Indian and Peruvian kids, studies found higher SES Canadians speak earlier.

 

279 - But a study showed, not SES, but syntax complexity accounts for earlier starting.

Written language has only existed for about 5,000 years.  So it is a clear example of cultural evolution.

 

LANGUAGE AND SOCIOCOGNITIVE SOCIALIZATION

281 – “psychologizing” is a vision of language as a part of socialization.  In it laguage use is correlated with children’s behavior.   Here we look at language as either reflecting or having and impact on thought.   For example, kids whose mothers talk about their feelings are more prosocial.  Language socializes and adjusts kids to the culture by molding them.

 

282 – Food is oppositional in American families and pleasurable in Italian ones.

Japanese children are socialized to command the strategies of indirection and intuitive socialization.

 

Thus language both molds the child and creates ‘culturally specific subjectivities.”

 

CHAPTER FIFTEEN: PHYLOGENETIC MODELS OF LANGUAGE CHANGE: THREE NEW QUESTIONS

By Russell D. Gray, Simon J. Greenhill, and Quentin D. Atkinson

Page 285

 

ABSTRACT:

Computational methods derived from evolutionary biology are increasingly being applied to the study of cultural evolution.  This is particularly the case in studies of language and evolution, where phylogenetic methods have recently been used to test hypotheses about divergence dates, rates of lexical change, borrowing, and putative language universals.  This chapter outlines three new and related questions that could be productively tackled with computational phylogenetic methods: What drives language diversification?  What drives differences in the rate of linguistic change (disparity)? And Can we identify cultural and linguistic homelands?

 

287 – The recent advances in language phylogenics has been reviewed by Levinson and Gray in 2012. “Tools from evolutionary biology Shed new light on the diversification of languages. Trends cognitive science.

 

WHAT DRIVES LANGUAGE DIVERSIFICATION

287 – There are around 7,000 languages and 194 language families.  Most of these language families are found in a single group.  But, Niger-Congo and Austronesia account for 1/3rd of the total each (1,495 and 1,246 respectively).

 

Mayan and Malayo-Polynesian are about 4,000 years old.  But, they have 69 and 1,226 languages respectively.  So Mayans gave birth to one language every 58 years and the other, every 40 months.

 

New Guinea has over 900 languages; Russia has 105 (though much larger).

 

There are three types of language diversity:

1)     Alpha diversity (the number of languages at a location), - This is oly the product of language splitting events (cladogenesis).

2)     phylogenetic language diversity (the sum of the path lengths between a set of languages on a phylogenetic tree);

3)      language disparity (The overall amount of variation between languages).

 

289 – Trees are unbalanced, that is because much of the world’s linguistic diversity is a result of large scale expansion events.   Often this happens when agriculture comes in.  We also see a dynamic wherein a niche is filled and then growth stops. 

 

293 – Creating an ‘absolute design space’ (i.e., a standard measure of what constitutes a separate language and how to compare them, is difficult).

 

There are 140 different traits that characterize language and each has 4.6 variations.

 

294 – But diversification is a steady measuring baseline,.

 

294 – Bateson in 1935 created the term schismogenesis to note that groups exaggerate language differences to make ethnic barriers.  In 1987 Thurston called this esoterogeny.   It does seem that a lot of divergent accents and new words (though not grammar structures) happen at the time of splitting.  But, this only explains 10 – 33% of divergence.

 

CAN WE INFER CULTURAL AND LINGUISTIC HOMELANDS?  HOW DO LANGUAGE EXPANSIONS UNFOLD ACROSS A LANDSCAPE?

 

297 – Their model (using computers and large data bases) unambiguously says that Indo-European languages came out of The Anatolian homeland (present day Turkey).

 

CHAPTER SIXTEEN: CULTURAL EVOLUTION OF LANGUAGE

By Dan Dediu (DD), Michael Cysouw (MC), Stephen Levinson (SL), Andrea Baronchelli (AB), Morten Christiansen (MC), William Croft (WC), Nicholas Evans (NE), Simon Garrod (SG), Russell Gray (RG), Anne Kandler (AK), and Elena Lieven (EL)

- Page 303

 

ABSTRACT: This chapter argues that an evolutionary approach to language has not only given fruit, but holds the key to understanding many puzzling aspects of language, its change and origin. The chapter highlights misconceptions about evolutionary theory.  It explores the antiquity of language and sketches a general evolutionary approach discussing the aspects of function, fitness, replication, and selection, as well the relevant units of linguistic evolution.  In this context, the chapter looks at some fundamental aspects of linguistic diversity such as the nature of the design space, the mechanisms generating it, and the shape and fabric of language. Given that biology is another evolutionary system, its complex coevolution with language needs to be understood in order to have a proper theory of language.  Throughout the chapter, various challenges are identified and discussed, sketching promising directions for future research.  The chapter ends by listing the necessary data, methods, and theoretical developments required for a grounded evolutionary approach to language.

 

305 – Particularism holds that laws of cultural evolution do not apply to linguistics.  That the processes in natural selection and herein are very different.  But there  are reasons to reject this view:

 

Language is clearly biological.  Changes do follow some pattern.  We do not all know language perfectly and therefore have no variation for evolution to select.  We all know language imperfectly and are still learning. Vocabularies are still growing and developing – we have 460,000 words, Wayan Fijians have 31,000.  And some think the emergence of biology and continued evolution are different types of evolution or that continued evolution doesn’t happen.  They happen at different rates, but evolution continues and always will.

 

308 – We split from Neandertals and Denisovan around 500 KYA.  Homo Erectus was 1.8 MYA.  The evolution of FOXP2 and breathing control seems to be between 1.8 and .5 MYA.   But we think language emerged around 250,000 years ago.  But, some push it back to .5 MYA.

 

309 – CHALLENGE 1: TO WHAT EXTENT DO COMMUNICATION, LANGUAGE, AND SPEECH HAVE SEPARATE EVOLUTIONARY HISTORIES?

 

310 - To understand a function’s evolution, you must understand its purpose.  Here they look at language’s ability to coordinate joint action and the role of indicating social relationships.

 

It will be interesting for scientists to try to tease out which characteristics of language point to which role being pre-eminent: coordinating action or enabling social relations.    

 

It is interesting to note herein that grammar stays the same as accents mutate.  But, do they mutate more during schisms?

 

311 - Fitness is another important evolutionary mechanism.

 

From an individual’s point of view, having great command of language could attract more mates and followers.

 

From a group perspective, we may look at features that help survival.  Chinese having a standard written form helps knit the world’s largest polity.   They use classics to knit their community over millennia [FOR THE BOOK].  If they had a phonetic system it would favor / mirror one region’s pronunciation or another.   Certain uses can also distinguish a prestigious class in a community. 

 

Nouns are easier to borrow than verbs.

 

REPLICATION AND SELECTION IN LANGUAGE EVOLUTION

312 – Not much in the way of prediction has come from Dawkin’s meme theory.  [I guess it is hard to think of selection forces.  But, rhymes and turrets words perhaps . . . ]

 

313 – Genes as replicators are hard to nail down. A single gene may be distributed across multiple discontinuous sites. Several genes often work together to make a phenotype.  Two different genes may overlap or even be identical.   They may interact with each other in complex ways such that they form a network functioning as a unit.  So they are problematic focuses of inheritance.

 

As such a new paradigm of evolutionary theory is afloat: the Ecological evolutionary developmental biology or “eco-evo-devo.”  [This is huge.  It means the end of the Hamiltonian tyranny – for a book].

 

There are some parallels in language and evolution: for example, linguistic unites interact with one another in such a way that they for a unit.  It is nestled as in words contain sounds and constructions contain words).  Linguistic unites are also individual units and parts of wholes.

 

But what sort of units in culture and language replicate? Behaviors?

 

314 - CHALLENGE 2: CAN WE IDENTIFY THE SIGNATURE OF MECHANISMS FOR GENERATION OF VARIATION AND SELECTION IN LANGUAGE EVOLUTION?

 

People have noticed that shortening and phonetic considerations could bring change “going to to gonna  Cellphone to cell.  Another set of factors is social, the structure of adopter groups – size hierarchy etc.

 

Diversity –

Cladogenesis:  Why are there 7,000 languages?

 

315 - Many factors influence cladogenesis: 1) There being available space leads to niches to rise. 2) The tendency of humans to divide into in-group and out-group opposites.  3) Exogoamy, which requires group opposition.  4) The human ability to maintain cohesive groups is limited, so splits are inevitable; 5) there are more languages around the equator, possibly due to a longer growing season, allowing more self-sufficient groups; 6) multilinguaglism acts as a conduit for replicators and extends the range of interactors, allowing different groups to interact while maintaining separate languages.

 

“Still, most potential factors and explanations for language diversity and skewed patterns of language cladogenesis are strongly under-investigated.  It is unclear why there has been reluctance in linguistics to investigate such pressing questions further. Nevertheless, there are some early indications that language splits are somehow special, in the sense that both the basic vocabulary (Atkinson et al. 2008) and structural features (Dediu and Levinson) show punctuated evolution, change in both being accelerated around language splits.”  IN THE BOOK – the reason being application, the key to consilience.

 

Two areas of further research: looking macro: questions regarding the global prediction of linguistic diversity based on political, ecological, cultural and social structure (this is political IN THE BOOK).  And, looking at the micro. April 26, 2015 at 7:12 AM

 

 

316 – CHALLENGE 3: HOW DOES A THEORY OF LANGUAGE DIVERSITY LOOK?

 

Two aspects: the number of languages and the diversity between them.  “Linguistic cladogenesis is produced when speech communities split, and thus factors which promot group boundary formation are also likely to produce more languages.  Possible factors include migration, environmental heterogeneity, increases in population size, and selection that favors some groups over others.  Possible factors that drive disparity include group size, social network density, contract with other languages, and the social processes of schismogenesis (esoterogeny).  What we need now are formal theories of the relationships between these variables.”  [IN THE BOOK]

 

CHALLENGE 4: CAN WE BUILD A GLOBAL TREE OF ALL KNOWN LANGUAGES?

 

How Does Cultural Evolution Explore the Design Space of Languages?

There are so many variables, it is hard to know, again, what to compare.

317 - We need characteristics that go back in time and are traceable.

318 – What does writing do to the design space?

319 – SOV, SVO and VSO account for 96% of the world’s languages

320 – Lastly, can we seek external factors, like genes and social demographics, that correlate with particular design choices?

 

CHALLENGE 5: CAN WE FORMULATE A TOTAL DESIGN SPACE THAT CAN SERVE AS A BASIS FOR WORLDWIDE LANGUAGE COMPARISON?

 

THE SHAPE AND FABRIC OF LANGUAGE

321 – Do languages and civilizations follow a tree like descent?

 

Vocabulary seems to be inherited as a unit.

 

CHALLENGE 6: What are the relative contributions of vertical and horizontal processes in language evolution?

 

CHALLENGE 7: HOW MUCH OF LANGUAGE CONSISTS OF SUBSYSTEMS OF TIGHTLY INTERLINKED TRAITS?

 

323 - CHALLENGE 8: HOW DOES THE STUDY OF LANGUAGE DEVELOPMENT and LANGUAGE EVOLUTION INFORM EACH OTHER?

Language skills arrive in a sequence: turn taking, intention reading, coordinated action, comprehension, simple syntax, fully accurate phonology, complex syntax. 

 

Can this inform the processes involved in evolution?  Language has evolved to be as learnable as possible.  This may place constraints on forms language can take.

 

COEVOLUTION OF BIOLOGY, CULTURE, and LANGUAGE

Biology and language:              

It is undeniable that language and biology have coevolved in the early phase of language.  The shapes of our larynx. 

While many think biology has since become frozen.  The authors herein do not think so: Language adapts to brains, the vocal tracts and the hands of speakers.

324 – Also language feedbacks on cultural evolution and so possibly influences our biological evolution.  We see this in culture’s nouns and the shapes of their mouths.  Thus we could use this to trace language’s evolution.

 

Vocabulary size is somewhat heritable as is short-term memory buffer size.

 

325 – And, while there seems to be pressure to larger brains, the shape is culturally determined.  We now have brain architecture dedicated to reading via recruitment.

 

CHALLENGE (: WHAT IS THE EVIDENCE FOR GENE-LANGAUGE COEVOLUTION? IS THERE ANY OTHER EVIDENCE BESIDES SPEECH?

 

326 - This is like the domestication of plants and animals feeding back on our immune and digestive tracts.

 

SOCIAL STRUCTURE AND LANGUAGE

Interactive network links allows more error correction than tv.  How do words propagate through systems, he asks.

 

CHALLENGE 10: WHAT ARE THE EFFECTS OF DEMOGRAPHY ON LANAGUAGE CHANGE AND DISPERSAL.

 

They found a group of 70 in Central America with a stable language.  But, having larger groups seems to stabilize language. [what of spreading your language by killing?  They are far too academic under this heading.]

 

The article goes on to offer many future directions and methods, but it has no clue as of yet, except to say that we need to get more info, integrate it, and use evolution as a glue in our theories and methods.

 

PART FOUR – RELIGION

 

CHAPTER SEVENTEEN: EVOLUTION OF PROSOCIAL RELIGIONS

By Edward Slingerland, Joseph Henrich, and Ara Norenzayan

Page 335

 

ABSTRACT: Building on foundations from the cognitive science of religion, this chapter synthesizes theoretical insights and empirical evidence concerning the processes by which evolutionary processes driven by intergroup competition may have shaped the package of beliefs, rituals, practices, and institutions that constitute modern world religions.  Five different hypothesized mechanisms are presented through which cultural group selection may have operated to increase the scale of cooperation, expanded the sphere of trustworthy interactions, galvanized group solidarity, and sustain group-beneficial beliefs and practices.  The mechanisms discussed involve extravagant displays, supernatural monitoring and incentives, ritual practices, fictive kinship, and moral realism.  Various lines of supporting evidence  are reviewed and archaeological and historic evidence  is summarized from early China (roughly 2000 bc-220bce), where prosocial religion and rituals coevolved with societal complexity.

 

335 – Most models assume kinship, reciprocity and reputation made large scale societies possible. But they don’t capture the extent of our sociality.

 

336 - Kinship doesn’t explain non-kin cooperation. And reciprocity and reputation don’t get us past villages.

 

Costly religious behaviors (rituals, building huge tombs, and debilitating taboos) also seem to defy evolutionary logic.  

 

But these evolve to deepen group solidarity, sustain internal harmony, galvanize trust and cooperation on a large scale and motivate further spreading.  Central are supernatural agents or forces that 1) moralize human action in particular and predictable ways; 2) incentivize certain behaviors; and 3) manipulate our psychology in ways that favor competition with other groups.

 

They will look at China cause it is often held up as a counter example to the utility of religion.

 

POINTS OF DEPARTURE

337 – Cognitively, religion is more intuitive than other modes of thought, say scientific.   Theory of mind, for example.   We also may have developed an ability to hold mental representations about life after death.  And, dualistic thoughts about mind being separate from body apply herein.

 

While foundational, this work leaves unexplained a) the distribution of different kinds of supernatural beliefs, b) the cultural evolution of religious representations over time, and c) why people are emotionally committed to some supernatural beliefs and not others.

 

Paleolithic gods were different than those that have arisen over the prior 5,000 years.  They were weak, whimsical, and morally ambiguous.

 

338 - They rely on ideas like us being biased to follow those with prestige (God) and absorb cultural info over our own perspective.  “We have evolved to have faith in culture, with this faith being directed by certain salient cues.” IN THE BOOK!

 

THE CULTURAL GROUP SELECTION OF BELIEFS, EXTRAVAGANT DISPLAYS, and RITUAL

 

Here they look at 5 ways that cultural group selection can assemble combinations of cultural traits that reinforce prosocial norms.

 

1)     Observing and participating in rituals likely induced deeper emotional commitment.

2)     Supernatural policing and incentives buttress norms.

3)     Religion extends cooperation.

4)     It uses fictive kinship to extend norms.

5)     Religion grounds norms in the structure of the universe!

 

339 - Costly Displays and Religious Faith

We give weight to CREDs (credible enhancing displays).  This could be coupled with the growing importance of low-arousal, high-frequency rituals, and the relative demphasis of high arousal, low frequency rituals with the expansion of the societal complex.

 

340 – A review of 83 utopian communities from the 19th century showed those with costlier rituals lasted longer.  Also, religious kibbutzim cooperated more in a behavioral experiment.  Attendance in religious functions also predicts Islamic martyrdom as well as reported willingness to die for ones God in other groups.  Also, a study of 60 small-scale societies found those in the most competitive socioecologies (with frequent warfare) endure the costliest rites.

 

341 – Another study found rituals became much more formal, elaborate, and costly as societies developed from foraging bands into chiefdoms and states.  

 

This also explains the linkage between early civilizations, religion, and monumental architecture.  This can be seen as a costly display by leaders.  And, they present an omnipresent religious prime.

 

342 – Early China’s most prominent archeological record is enormous tombs. These were buried, but signaled wealth beforehand.  The Shang elites spent most of their time involved in time consuming and costly sacrifices to ancestral spirits.  This likely consumed 10 % of societies money and all the elites’ time.

 

Supernatural policing

Abrahamic religions obviously have this.  But, evidence shows lords were always placating gods. The mandate of heaven is vital to the Zhou dynasty.  By the 5th BCE, as the Zhou falls, texts show faith in ghosts and spirits must be fostered to create moral belief.

 

343 - Rituals of Collective Effervescence -

Durkheim wrote about rituals putting the group into action.  He noted how they use music, rhythm and synchrony to build up solidarity. 

 

Growing evidence suggests that acting in synchrony, by marching, singing, or dancing in rhythm increases feelings of affiliation, empathy, compassion, and connectedness, even among strangers.   Music promotes prosociality in preschoolers too.

 

344 – This is why militaries use them, no doubt.

 

Fictive kin -  

By calling people ‘brother’ either kinship psychology mechanisms are triggered OR we learn how we are supposed to relate consciously.

 

Early Chinese texts also have this family language. 

345 – Confucianism very much tries to infuse a familial emotions into public life.  Mencius tried to train people for familial extension feelings, so he has the weak extension above.

 

Moral realism

Moral realism is the belief that your moral intuitions are grounded in the metaphysical structure of the universe.  This justifies their force and their imposition on others.

 

Weak evaluations are like “I like ice cream.”  But, strong evaluations are based on implicit universal claims, and so seem to have objective force – Charles Taylor says.

 

We punish violations of strong evaluation, like abusing small children.

 

346 – Much anthropological evidence indicates little or no connection between the moral and supernatural domains in small-scale human societies.

 

As we see in the Middle East when norms are associated with the supernatural, they become emotionally charged and less subject to material calculations.

 

The Chinese Zhou had a supernaturally vindicated mandate.  Confucious thought himself sent by Heaven. Mencius naturalized this a bit by seeing morality in everyone’s individual nature. But this endowment still came from heaven.

 

RELIGIOUS DIVERSITY AND THE RISE OF LARGE-SCALE CIVILIZATIONS

In Liberia, the belief in witchcraft is undermining social cooperation; not all are prosocial.

 

The religions discussed herein are the ones that forged links between prosociality, morality, rituals, and deep commitments to supernatural agents.  These could outcompete others.

 

This theory has some backing, but requires more data.

 

CHAPTER EIGHTEEN: RETHINGING PROXIMATE CAUSATION AND DEVELOPMENT IN RELIGIOUS EVOLUTION

- By Harvey Whitehouse

- Page 349

 

ABSTRACT:  Efforts to understand cultural evolution, and its articulation with biological evolution, have tended to focus on problems of ultimate rather than proximate causation; that is on issues of function and selection rather than of mechanisms and development.  Although we now have sophisticated models of multilevel selction and gene-culture coevolution, we lack a similarly sophisticated account of the various levels at which proximate explanation needs to be understood.  This chapter attempts to sketch out a more sophisticated framework for proximate explanation in religious evolution, inspired by C. H. Waddington’s notion of the “epigenetic landscape.”  Building on this idea, three kinds of landscapes are disambiguated: epigenetic, cognitive-developmental, and socio-historical. The discussion here focuses on religious phenotypes, but the general approach would be applicable to cultural practices more generally. The aim is to bring greater conceptual clarity and integration to a somewhat complex and messy cluster of research areas and, at the same time, open up new hypothesis ripe for investigation.

 

INTRO

The biological, mental and social are often analyzed separately.

 

350 – Waddington made a metaphor of a tent on a landscape and the pegs were genes and the ropes effects of the genes.  The landscape the sum of the genes.  Steepness was plasticity, steepness, genetic canalization; and “end state” attractor, a stable community or tradition.

 

EPIGENETIC LANDSCAPES and RELIGIOUS BODIES

 

353 - Transcendence in the brain has been related to reduced activity in the parietal lobe.  Religious traits are phenotypes.  

 

For example, religious rituals (and cultural rituals of all kinds) activate a cluster of precautionary brain systems (as cleaning, straightening).  This can be useful, cleaning, but OCD folks have it to excess. [very Julian Jaynes].  These behaviors appear around 2 years of age and peak prior to puberty.

 

354 – There is evidence that OCD behavior peaks in women during pregnancy and in men after the birth of their first child.   Some religions – Judaism – have heavy ritual that would build on this ‘basin of attraction.”

 

355 – COGNITIVE – DEVELOPMENTAL LANDSCAPES AND RELIGIOUS THINKING

These Basins of attractors are expressed in a cognitive – developmental landscape.

 

The interaction of cognitive canalization and cultural learning in development results in more or less stable ‘semantic networks’ in the mind.   Some of the nodes in semantic networks are easier to represent, believe or remember than others.

 

Disembodied being seems to be universal. It is intuitive and easy to represent.

 

357 - Our teleological willingness to attribute purpose to the natural world helps religion exist. Our intuition about immanent justice makes it easier to absorb counterintuitive morality.   Some nodes are more canalized than others.

 

Emotion enhancers and repetition increase our willingness to believe. Narrative can make religious doctrines more memorable as well as coherent and believable [IN THE BOOK]. 

 

SOCIO-HISTORICAL LANDSCAPES AND RELIGIOUS TRADITIONS

We can share public understandings by speech, text, or body decoration.  “The sum of all people’s semantic networks in a bounded population can be described as a “sociocultural system.”” 

 

358 – We can again use the tent metaphor at this level.

 

359 – The epigenetic, cognitive-developmental and socio-historic shape and constrain each other.

 

360 – Cargo cult leaders used our intuitions to foretell of great imbalances would be reversed and the dead would be reincarnated, and the cargo would materialize.  [Intuition + narrative].

 

The Kivung cargo cult lasted much longer than others.  It was in a larger group too. Its doctrine became systematized and remains the same.   

 

361 – It did so by frequent repetition at public gatherings. This got their creed elaborated.  It put interpretations into memory.  This would impact neural processes involved in semantic memory, rote learning, narrative construction, oratorical expertise and homogenize thought at the population level.

 

362 – The Kivung outlawed betel juice chewing. This made their teeth better and them more attractive.  They married more and became more endogamous.  This sharpened their in-group / out-group awareness.

 

This is used to show how different levels interact.  We cannot just look at brain level explanations or gene level or sociocultural.   

 

 

CHAPTER NINETEEN: RELIGIOUS PROSOCIALITY: A SYNTHESIS

- By Ara Norenzayan, Joseph Henrich, and Edward Slingerland

- Page 365

 

ABSTRACT:

Religion is a ubiquitous aspect of human culture, yet until recently, relatively little was known about its natural origins and effects on the human mind and societies.  This is changing. Debates about the evolutionary origins and functions of religion, including its origins in genetic and cultural evolution, hinge on a set of empirical claims about religious prosociality: whether, through which particular pathways, certain religious beliefs and practices encourage prosocial behaviors. Here we synthesize and evaluate the scientific literature on religious prosociality, highlighting both gaps and open questions.  Conferring evidence from several fields suggests a nuanced pattern such that some religious beliefs and practices, under specific sociohistorical contexts, foster prosocial behaviors among strangers.  This emerging picture is beginning to reveal the psychological mechanisms underlying religious prosociality.  Further progress will depend on resolving outstanding puzzles, such as whether religious prosociality exists in small-scale societies, the extent to which it is constrained by in-group boundaries, and the psychology underlying various forms of disbelief.

 

365 – Religion seems to facilitate acts which benefit others at personal cost; prosociality. 

 

SURVEYS OF RELIGIOSITY and SELF-REPORTED CHARITABILITY

366 – People of all religions in the US donate more and volunteer more.

367 – But is this just in-group charity? These are also, self-reported, so possibly biased and not true.

 

CORRELATING RELIGIOUS INVOLVEMENT and PROSOCIAL BEHAVIOR

Studies have found no connection between religiosity and prosocial behavior, except a study that found religious kibbutzim take less of a total of offered money than others. Afro-Brazilians and Muslims too.

 

369 – Again, herein we note that early gods are less powerful and less tied to morality.  “As societies get larger and more complex . . . ritual. . . becomes more frequent and dogmatic.  A survey of 87 nations found folks who believed in a personal god more harshly condemned many moral transgressions.

 

RECONCILING INCONSISTENT FINDINGS ON RELIGIOUS PROSOCIALITY

370 – These studies are often done on college students where religious reminders are infrequent.  They also ask y ou to benefit anonymous folks, not ingroups, lastly, the null results happened in nations that are weird (western, educated, industrialized, rich and democratic).  371 – Strong secular states reduce dependence on religion for a source of morality.

 

Also, religion might make you prosocial, but prosocial folks may also become religious.

 

EXPERIMENTAL EVIDENCE: RELIGIOUS PRIMING.

372 - Priming has a strong effect in sharing in experiments.  But an experiment in Canada showed that this effect disappeared for Christians when the money was to go to Muslims.

 

WHY DO RELIGIOUS REMINDERS INCREASE PROSOCIALITY?

373 -  It could be the omniscient watching curbs bad behavior.  Wearing sunglasses – associated with anonymity – reduces good behavior.

 

But behavioral priming could also start and ‘ideomotor’ account -  a religious suite of generous predispositions, so to speak.


It could be both, the watcher and the suite.  But the watcher would be consistent with a harsher God and the suite a more benevolent view of God.

 

375 – On meta study found priming only consistently worked on religious folks.  This backs the idea that the religious culture, not innate ideomotor functions make religion salient.   But these studies have been done with atheist college students.

 

Interestingly some studies show belief in a benevolent god INCREASES cheating.  Belief in hell drops crime rates.  These accounts are hard to square with the ideomoter account as it would produce the opposite effect. 

 

ETHNOGRAPHIC and HISTORICAL EVIDENCE: HOW SUPERNATURAL MONITORING CONTRIBUTED TO LARGE-SCALE PROSOCIALITY.

 

377 – In a review of 427 societies, Stark found only 23.9 acknowledge a god who is active in human affairs and supportive of human morality.  Religions with such Gods are peculiar.  Yet, most today live under them.  Roes and Raymond (2002) found that the bigger the group size, the more likely the group has a culturally sanctioned omniscient, all-powerful, morally concerned deity who directly observes, rewars and punishes for social behavior.

 

378 – An analysis of religious 19th century American communes found they outcompeted and outlasted secular ones.  And, this was statistically explained via costly displays and restrictions on behaviors.

 

OUTSTANDING QUESTIONS

We should study small surviving societies’ priming effects.

We should study atheists.  If none react to priming, this is ‘cultural evolution theory.’  If some do, ideomotor.

Study if secular institutions lead to the decline of religion.  This would indicate if it is hardwired or cultural. 

We should study which kind of prosociality gets impacted by what kind of religion.

Also, does prosociality stop at the boundaries of the in-group?

 

CHAPTER TWENTY: THE CULTURAL EVOLUTION OF RELIGION

By Joseph Bulbulia (JB), Armin W. Geertz (AG), Quentin D. Atkinson (QA), Emma Cohen (EC), Nicholas Evans (NE), Pieter Francois (PF), Herbert Gintis (HG), Russel D. Gray (RG), Joseph Henrich (JH), Fiona M. Jordon (FJ), Ara Norenzayan (AN), Peter J. Richerson (PR), Edward Slingerland (ES), Peter Turchin (PT), Harvey Whitehouse (HW), Thomas Widlok (TW), and David S. Wilson (DW).

 

Religion may be one factor that enabled large-scale complex human societies to evolve.  Utilizing a cultural evolutionary approach, this chapter seeks explanations for patterns of complexity and variation in religion within and across groups, over time.  Properties of religious systems (e.g. rituals, ritualized behaviors, overimitation, synchrony, sacred values) are examined at different social scales, from small-scale foragers to large-scale urban societies.  The role of religion in transitional societies is discussed, as well as the impact of witchcraft, superhuman policing, and the cultural evolution of moralizing gods. The shift from an imagistic to a doctrinal mode of religiosity is examined, as are the relationshiops between sacred values and secular worlds.  Cultural evolutionary approaches to religion require evidence and methods from collaborative  and multidisciplinary science.  The chapter concludes with an overview of several projects that are working to provide conceptual, methodological, and empirical groundwork.

 

Why TAKE A CULTURAL EVOLUTIONARY APPROACH TO RELIGION?

 

382 – Religions vary, but they are not random, they tend to come in packages.  These include, “beliefs in superhuman persons or powers, ritualized behaviors, devotions and pieties, mythologies, values, goals, and moral doctrines.”

 

383 – Some features, like specialized religious casts are only in some religions.

Current research looks at the role that coordination and competition have played.

 

Though there are many questions, there are nine points of agreement. 

384 – 1) Human minds exhibit reliably developing features of cognition and emotion.  We are adapted cause we transmit info through the generations.

2) Cultural systems accumulate design features from selection, biased adoption decisions and non-random innovations. This impacts genetic evolution and this, in turn, impacts culture.

3) The capacity for culture is a coevolutionary adaption; prestige and conformity biases appear to be ancient and nearly universal.  We need to understand culture and biology to understand all of these.

4) (385) To underscore their inherently functional properties, cultural systems can be defined as “meaning systems.” Meaning systems are designed to receive environmental information as input and to generate action as output.

5) We can better understand both human brains and human meanings systems by studying how they interact.

6) Religious meaning systems appear to link environmental info, especially symbolic info, with behavior outputs, especially social behaviors.

7) Religions include pragmatic elements. Religions all have costly rituals and beliefs in superhuman entities.  But what are the functional elements?

8) This does not mean every element is functional.  Nor does it mean that individual and group level functions converge.  Traits that aren’t adaptive must evolve along with adaptive ones. We must study what promotes their conservation and transmission.

9) Religious meaning systems interact with political, technological, and linguistic meaning systems, and environmental changes. The full range of ecological relationships among groups can potentially exist (competition, predation, parasitism, mutualism, communalism, and coexisting without interacting).

 

RELIGIOUS ELEMENTS AT DIFFERENT SOCIAL SCALES

 

Religion in small-scale societies: Rituals.

 

386 – The smallest human groups are around 50, but interact with other groups.  So they are heavily social beyond any other animal.  It is unparalleled that we do not only cooperate with close kin. We have “ultrasociality.”

 

387 – Religions facilitate cooperation across multiethnic and linguistic divides. Rituals are one method for doing this.

 

Ritual performances are in even the most egalitarian foragers.  Ritualized gift giving is a route for creating obligations. 

 

Overimitation:

Recent evidence suggests “overimitation” may have been a crucial adaptation in the evolution of both language and of social norms.  It is a copy-now, correct later process.  And, more rigid forms of overestimation support affiliation and the learning of norms. Ritual actions synchronize groups, overimitation seems to stabilize norms.

 

Synchrony:

Although sacrificing to a stature or considering goat guts patterns seems inefficient for action planning, yet religious thinking has bonding functions. 

 

389 – Once says synchrony “coevolved biologically and culturally to serve as a technology of social bonding.”   

 

Why should chanting, singing, shouting and marching rhythmically effect group unity?

 

A study asked people to join in various levels of synchrony from passing cups at the same time to singing Oh Canada.  Those who sang and moved sustained higher levels of cooperation over team.  They reported a) enhanced feelings of being on the same team and b) greater subjective perceptions of similarity to their coutnerparts.   They trusted each other more.  (Wiltermuth and Heath 2009). 

 

Synchrony and Sacred Values -

Fischer compared 9 naturally occurring rituals in New Zealand.  He looked at stated and revealed (acted upon) prosociality.  Those with body movement and those judged sacred bonded the most.

 

391 - Ritual signaling –

How do cooperators avoid defectors and assort?

Expression wouldn’t do it, language, because people can lie easily.

There is costly signaling in nature and humans.

Wherever local social, economic, and ecological conditions can influence cultural evolution such that the functions of rituals may vary over time, those that do a better job of screening cheaters will win out; costly signaling evolves.

 

At some stages ritual might integrate. At others it might show social differentiation. 

 

392 - Circumcision rituals of the Merina were family rituals in 1780, became state rituals with royal circumcision, then different meanings, including anti-Christian in the 1960s.

 

That is a good hard-to-fake belonging ritual.  

 

Rituals must tap into the sacred and can be neo-traditions.  Christianity is good at this in that it shifts to different meanings well.

 

Dysphoric and Synchronous Arousal.

Recent evidence suggests that rituals coordinate empathetic arousal among audiences and performers.

 

Connected spectator’s hearts synchronized with fire walkers, but not unconnected.  You had to know a participant.

 

Dysphoric (painful or frightening) rituals have also been observed to bolster solidarity among initiates.  

 

393 – Dysphoric rituals – in a study of 644 – were shown to correlate negatively with agricultural intensity.  So they may be necessary where cooperation problems are rampant, like big game hunting.  These usually happen during late adolescence.

 

RELIGION IN TRANSITIONAL SOCIETIES: SUPERHUMAN POLICING

 

“Over time, cultural evolution, driven by intergroup competition, can aggregate and calibrate a system of interlocking beliefs, practices, and values that extend cooperation and enhance internal harmony.”

 

Witchcraft -

395 - Fear of being a witch in Hopi tribes drives people to virtuous action: low ambition, friendliness, and hospitable comport. This avoids witch jealousy.   It promotes prosociality. 

“So witchcraft could be viewed as a kind of narrated ethics. Expressing more or less defined models of thought and behavior that stage social and personal identities in conventional narratives.”

But sometimes witch persecutions destabilize.  So may not hold up in inter group conflict.

 

Within groups we have cycles, between groups we have trends, towards group solidarity and he decline of corrosive antisocial traits.

 

396 – Thus we can make predictions based on how much intergroup competition there is.   This can be looked at by cultural comparative phylogenetics.   What features of witchcraft happen when?  What language do we see at what stage and in what settings?

 

Superhuman policing and the cultural evolution of moralizing gods.

How did the transition to moralizing Gods in larger societies happen?

Wright has argued that ancestor gods do not control the larger community, only your family.  

 

398 – Some chiefdoms have punishment for individuals by Gods.  They do this inconsistently though.  And, they favor stability by endowing chiefs with divine wisdom and power.   Such gods are not, however, omniscient, omnipotent and benevolent.  These are the religions that competed as states began to form.

 

Wright, R, the evolution of god (2009) looked at the evolution of Abrahamic God from tribal and whimsical to more unitary and supreme.

 

399 – Surveillance by morally concerned superhuman agents also appears as a prominent theme in early China.   Heaven gave moral norms.  Failure to follow the behavior or thought invited instant superhuman punishment.

 

Priming only unambiguously impacted those who had previously donated to religious charities.

 

Perhaps people are so good in secular communities that religious primes don’t make much of a difference? And, differences in atheist responses may point to genetic differences.

 

THE SHIFT FROM AN IMAGISTIC TO A DOCTRINAL MODE OF RELIGIOSITY.

In small – scale societies rituals are less frequent and more intense.  When states come, the dysphoric rituals decline – except in small pockets like military hazing.  Doctrinal narrative becomes more standardized. Sacred texts codify.  

 

401 – Religious structures become more hierarchical.    All is less intense, public repetition just serves to reinforce the narrative.

 

CREDIBILITY ENHANCING DISPLAYS (CREDs)

CREDS are especially important for teachers.  This signals true belief.

 

402 – Sacred values are enshrined in religion.  In the West Bank people will not sell their land, it was given to them by God. 

Secular people too, perhaps, also consider some truths sacred.

Do moral judgments require grounding in supernatural stuff to make them true. 

Charles Taylor says, ‘yes’ and so secularists ground it in “self-evident faith in human rights, human dignity, freedom, etc.)

 

403 – SUMMARY

Religion may be the cornerstone of the evolution of large-scale complex human societies.

APPENDIX:

Do the mechanisms of cultural evolution play similar roles in the acquisition of different cultural behaviors (language, tool use, social norms)? 

 

Great question finally, “Are adolescent brains wired differently for norm absorption?”  Why have women’s puberty times fallen so in tech-advanced societies?  Why is the prefrontal cortex not fully mature until a person is in their mid-twenties?

 

HOW DO WE MEASURE CHILDHOOD ACROSS CULTURES?

Is it when people produce more calories than they eat?

Changes in rights and obligations?

Rituals?

 

Adaption of human systems to be learned by human cognitive apparatus.

Language must be learnable.  It is shaped by our cognitive biases.   

 

We have many cognitive capabilities that facilitate cultural learning’s. For example, joint attention, pointing, imitation.  Infants do these.  And they emerge on a timetable.

 

Children play a role in restricting in-group variation. They enforce norms and ostracize.  They match their behavior to the majority and like to play with others who are like them.

 

Adolescents seem to be on the forefront of changing language.

 

Is the length of childhood related to the overall complexity of a society?  Long childhood allows the development of complex technology, literacy.

Though not net producers until 18, and at their peak until 30, children do seem to produce earlier in simpler societies.