The Origin and Evolution of Cultures (III)

I have read almost three-fourths of the book by now. In this post I have quoted extensively from chapter 14 because this chapter is somewhat different from most of the other chapters in the book; it has no math, but it has a lot of observations which relate to the work they’ve covered in previous chapters, and it’s much easier to blog than most of the stuff in this book.

I don’t always agree with the authors about the details and about the conclusions they draw, but this book is consistently interesting and provides high-quality coverage of the topic in question. Unless things go seriously downhill during the last part of the book, I’ll give it five stars on goodreads.

I wrote some comments and personal observations along the way when I wrote this post, many of which are not closely related to the book coverage. I have posted them below the quotes from the book, in the second half of the post proper. I actually did earlier on make the decision not to include the stuff I’d written in this post at all because I didn’t like what I’d written, but after making a few revisions I changed my mind. I may change it again. Either way writing about these things, rather than just reading about them, is a great way to force yourself to think more carefully about them.

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“Evolutionary explanations are recursive. Individual behavior results from an interaction of inherited attributes and environmental contingencies. In most species, genes are the main inherited attributes, but inherited cultural information is also important for humans. Individuals with different inherited attributes may develop different behaviors in the same environment. Every generation, evolutionary processes — natural selection is the prototype — impose environmental effects on individuals as they live their lives. Cumulated over the whole population, these effects change the pool of inherited information, so that the inherited attributes of individuals in the next generation differ, usually subtly, from the attributes in the previous generation. Over evolutionary time, a lineage cycles through the recursive pattern of causal processes once per generation […] Note that in a recursive model, we explain individual behavior and population-level processes in the same model. Individual behavior depends, in any given generation, on the gene pool from which inherited attributes are sampled. The pool of inherited attributes depends in turn upon what happens to a population of individuals as they express those attributes. Evolutionary biologists have a long list of processes that change the gene frequencies, including natural selection, mutation, and genetic drift. However, no organism experiences natural selection. Organisms either live or die, or reproduce or fail to reproduce, for concrete reasons particular to the local environment and the organism’s own particular attributes. If, in a particular environment, some types of individuals do better than others, and if this variation has a heritable basis, then we label as “natural selection” the resulting changes in gene frequencies of populations. We use abstract categories like selection to describe such concrete events because we wish to build up — concrete case by concrete case — some useful generalizations about evolutionary process. Few would argue that evolutionary biology is the poorer for investing effort in this generalizing project. Although some of the processes that lead to cultural change are very different than those that lead to genetic change, the logic of the two evolutionary problems is very similar.”

“Evolutionary theory is always multi-level […] evolutionary theories are systemic, integrating every part of biology. In principle, everything that goes into causing change through time plays its proper part in the theory. […] In theorizing about human evolution, we must include processes affecting culture in our list of evolutionary processes along side those that affect genes. Culture is a system of inheritance. We acquire behavior by imitating other individuals much as we get our genes from our parents. A fancy capacity for high-fidelity imitation is one of the most important derived characters distinguishing us from our primate relatives […] We are also an unusually docile animal (Simon 1990) and unusually sensitive to expressions of approval and disapproval by parents and others (Baum 1994). Thus parents, teachers, and peers can rapidly, easily, and accurately shape our behavior compared to training other animals using more expensive material rewards and punishments. […] once children acquire language, parents and others can communicate new ideas quite economically. Our own contribution to the study of human behavior is a series of mathematical models in the Darwinian style of what we take to be the fundamental processes of cultural evolution”

“We make [the] claim that a dual gene-culture theory of some kind will be necessary to account for the evolution of human cooperative institutions. Understanding the evolution of contemporary human cooperation requires attention to two different time scales: First, a long period of evolution in the Pleistocene shaped the innate “social instincts” that underpin modern human behavior. During this period, much genetic change occurred as a result of humans living in groups with social institutions heavily influenced by culture, including cultural group selection […] On this timescale genes and culture coevolve, and cultural evolution is plausibly a leading rather than lagging partner in this process. We sometimes refer to the process as “culture-gene coevolution.” Then, only about 10,000 years ago, the origins of agricultural subsistence systems laid the economic basis for revolutionary changes in the scale of social systems. The evidence suggests that genetic changes in the social instincts over the last 10,000 years are insignificant. […] Our hypothesis is premised on the idea that selection between groups plays a much more important role in shaping culturally transmitted variation than it does in shaping genetic variation. As a result, humans have lived in social environments characterized by high levels of cooperation for as long as culture has played an im portant role in human development. […] We believe that the human capacity to live in larger scale forms of tribal social organization evolved through a coevolutionary ratchet generated by the interaction of genes and culture. Rudimentary cooperative institutions favored genotypes that were better able to live in more cooperative groups. Those individuals best able to avoid punishment and acquire the locally-relevant norms were more likely to survive. At first, such populations would have been only slightly more cooperative than typical nonhuman primates. However, genetic changes, leading to moral emotions like shame, and a capacity to learn and internalize local practices, would allow the cultural evolution of more sophisticated institutions that in turn enlarged the scale of cooperation. These successive rounds of coevolutionary change continued until eventually people were equipped with capacities for cooperation with distantly related people, emotional attachments to symbolically marked groups, and a willingness to punish others for transgression of group rules.”

“Upper Paleolithic societies were the culmination of a long period of coevolutionary increases in a tendency toward tribal social life. We suppose that the resulting “tribal instincts” are something like principles in the Chomskian linguists’ “principles and parameters” view of language […] The innate principles furnish people with basic predispositions, emotional capacities, and social dispositions that are implemented in practice through highly variable cultural institutions, the parameters. People are innately prepared to act as members of tribes, but culture tells us how to recognize who belongs to our tribes, what schedules of aid, praise, and punishment are due to tribal fellows, and how the tribe is to deal with other tribes — allies, enemies, and clients. […] Contemporary human societies differ drastically from the societies in which our social instincts evolved. Pleistocene hunter-gatherer societies were likely comparatively small, egalitarian, and lacking in powerful institutionalized leadership. […] To evolve largescale, complex social systems, cultural evolutionary processes, driven by cultural group selection, takes advantage of whatever support these instincts offer. […] cultural evolution must cope with a psychology evolved for life in quite different sorts of societies. Appropriate larger scale institutions must regulate the constant pressure from smaller-groups (coalitions, cabals, cliques), to subvert the large-group favoring rules. To do this cultural evolution often makes use of “work arounds” — mobilizing tribal instincts for new purposes. For example, large national and international (e.g. great religions) institutions develop ideologies of symbolically marked inclusion that often fairly successfully engage the tribal instincts on a much larger scale. Military and religious organizations (e.g., Catholic Church), for example, dress recruits in identical clothing (and haircuts) loaded with symbolic markings, and then subdivide them into small groups with whom they eat and engage in long-term repeated interaction. Such work-arounds are often awkward compromises […] In military and religious organizations, for example, excessive within-group loyalty often subverts higher-level goals […] Complex societies are, in effect, grand natural social-psychological experiments that stringently test the limits of our innate dispositions to cooperate.”

“Elements of coercive dominance are no doubt necessary to make complex societies work. Tribally legitimated self-help violence is a limited and expensive means of altruistic coercion. Complex human societies have to supplement the moralistic solidarity of tribal societies with formal police institutions. […] A common method of deepening and strengthening the hierarchy of command and control in complex societies is to construct a nested hierarchy of offices, using various mixtures of ascription and achievement principles to staff the offices. Each level of the hierarchy replicates the structure of a hunting and gathering band. A leader at any level interacts mainly with a few near-equals at the next level down in the system […] The hierarchical nesting of social units in complex societies gives rise to appreciable inefficiencies […] Leaders in complex societies must convey orders downward, not just seek consensus among their comrades. Devolving substantial leadership responsibility to sub-leaders far down the chain of command is necessary to create small-scale leaders with face-to-face legitimacy. However, it potentially generates great friction if lower-level leaders either come to have different objectives than the upper leader ship or are seen by followers as equally helpless pawns of remote leaders. Stratification often creates rigid boundaries so that natural leaders are denied promotion above a certain level, resulting in inefficient use of human resources and a fertile source of resentment to fuel social discontent. On the other hand, failure to properly articulate tribal scale units with more inclusive institutions is often highly pathological. Tribal societies often must live with chronic insecurity due to intertribal conflicts.”

“The high population density, division of labor, and improved communication made possible by the innovations of complex societies increased the scope for elaborating symbolic systems. The development of monumental architecture to serve mass ritual performances is one of the oldest archaeological markers of emerging complexity. Usually an established church or less formal ideological umbrella supports a complex society’s institutions. At the same time, complex societies extensively exploit the symbolic ingroup instinct to delimit a quite diverse array of culturally defined subgroups, within which a good deal of cooperation is routinely achieved. […] Many problems and conflicts revolve around symbolically marked groups in complex societies. Official dogmas often stultify desirable innovations and lead to bitter conflicts with heretics. Marked subgroups often have enough tribal cohesion to organize at the expense of the larger social system. […] Wherever groups of people interact routinely, they are liable to develop a tribal ethos. In stratified societies, powerful groups readily evolve self-justifying ideologies that buttress treatment of subordinate groups ranging from neglectful to atrocious.”

“Many individuals in modern societies feel themselves part of culturally labeled tribal-scale groups, such as local political party organizations, that have influence on the remotest leaders. In older complex societies, village councils, local notables, tribal chieftains, or religious leaders often hold courts open to humble petitioners. These local leaders in turn represent their communities to higher authorities. To obtain low-cost compliance with management decisions, ruling elites have to convince citizens that these decisions are in the interests of the larger community. As long as most individuals trust that existing institutions are reasonably legitimate and that any felt needs for reform are achievable by means of ordinary political activities, there is considerable scope for large scale collective social action. However, legitimate institutions, and trust of them, are the result of an evolutionary history and are neither easy to manage nor engineer. […] Without trust in institutions, conflict replaces cooperation along fault lines where trust breaks down. Empirically, the limits of the trusting community define the universe of easy cooperation […] At worst, trust does not extend outside family […] and potential for cooperation on a larger scale is almost entirely foregone.”

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If I were the kind of person who were interested in political stuff, I might have decided to talk a bit about how the above remarks may relate to how to set up optimal policies aimed at maintaining cooperation and trust (perhaps subject to a few relevant constraints). Some ideas spring to mind, perhaps in relation to immigration policy in particular. But I’m not that kind of person, so I won’t talk about that here.

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I figured it might be a good idea to cover some ‘related’ topics here, as I can’t be sure how much the people reading along here has read about this kind of stuff and what kind of background people have. Many of the remarks below are only tangentially related to the coverage above, but they’re arguably important if you want ‘a bigger picture’.

One thing to note is that in the context of this part:

“only about 10,000 years ago, the origins of agricultural subsistence systems laid the economic basis for revolutionary changes in the scale of social systems. The evidence suggests that genetic changes in the social instincts over the last 10,000 years are insignificant.”

…there are at least two important points to mention. One is that the 10.000 years number is ‘just a number’, and that there is no ‘one true number’ here – that number depends on geography and a lot of other stuff. The origins of agriculture are still somewhat murky, though we do know a lot. There are lots of problems archaeologists need to deal with when analyzing these sorts of things, like for instance the issue that locally the date for first observed/established case of agricultural adoption may not correlate well with the first actual adoption date, because we have this tendency to overlook the sort of evidence that has already evaded attention for thousands of years. Another problem is that the switch was often gradual and took a lot of time, and involved some trial and error. A related point is that switches in food procurement strategies likely happened at local levels in the far past – in some areas of the world it would seem likely that a strategy of mostly relying on a few select crops (‘agriculture’) in ‘good periods’ (perhaps lasting hundreds of years) and then relying more on a more diversified set of different crops as well as other complementary food sources (‘hunter-gathering’) in ‘bad periods’ may have been superior to a strategy of relying exclusively on one or the other, especially around the ‘border areas’ where people almost couldn’t make agriculture work at all due to climatic factors. It’s incidentally worth noting that “no single plant can provide the mix of amino acids that primates need for growth, so primates must either eat a variety of different plants to achieve an adequate amino-acid balance, or have a regular supplement of animal foods in their diet”, so the ‘rely-on-only-one-plant agricultural model and nothing else’ is not workable in practice and never was (quote from Sponheimer et al., p.361. Less extreme versions of dependence on a single crop is feasible if you can get the other stuff elsewhere, but it’s highly risky – ask e.g. the Irish. Despite how far we’ve come in other areas, we humans incidentally rely on quite few crops to supply a substantial part of the calories we need, making us somewhat vulnerable; for example more than one-fifth of all calories consumed by humans are derived from rice). Yet another problem is that ‘agriculture’ isn’t just ‘agriculture’ – people got better at this stuff over time and things like intensification and yield improvements were important, yet often difficult or frankly impossible to estimate, especially at the intensive margin. This means that ‘we think agriculture started here in 8900 BC’ may in some contexts not mean quite what you could be tempted to think it means.

But the above, and many related, issues aside, of course the main problem with a statement including words like ‘about 10,000 years ago’ is that the variation in when different people living different places ‘adopted agriculture’ (whatever that may mean) is astonishingly huge. Here are two illustrative passages from Scarre et al. – exhibit 1: “The site of Ohalo II in northern Israel, dated around 20,000 BC, provides a remarkable snapshot of lifeways in the Levant during the Last Glacial Maximum […] At Ohalo II […] we have evidence for the exploitation of a broad spectrum of plants and animals, the extensive use of storable plant foods, and the year-round occupation of a settlement. The starch traces found on the surfaces of grinding stones confirm that they were indeed used in the preparation of hard-seeded plant foods.” The site is a hunter-gatherer site, but these guys belonged to a sedentary hunter-gatherer settlement inhabited by people who were doing many, though not all, of the things we usually only associate with traditional farmers, illustrating how these sorts of categorizations sometimes get slightly complicated if you’re not very careful when you define your terms (and sometimes even if you do) – and perhaps illustrating that it makes sense to be cautious about which mental models of our hunter-gatherer forebears we apply. Either way more ‘proper’ farming communities, such as these, which started to pop up during the early Neolithic were themselves likely at least in part ‘the result’ of gradual changes that humans which came before them had had on their surrounding environments (especially local flora and fauna – in terms of the latter probably especially our impact on local megafauna) – the processes which eventually lead us to agriculture probably took a lot of time, though just how long into the past you need to look to get the full picture is an open question, and probably will remain so as the amount of evidence available to us is sparse (which impact had human activities taking place during the late Pleistocene had on the range and distribution of potential domesticables at the beginning of the Holocene? Such questions do not to me seem easy to answer, and they’re part of the story). Although agriculture in some areas of the world by now has a ‘shelf life’ of 10.000 years or more, in other areas of the world that ‘shelf life’ is much, much shorter – exhibit 2: “no agricultural colonization of Australia, the last completely hunter-gatherer continent to survive until European contact, ever occurred.”

Agriculture provided the economic foundation for achieving the scale of social complexity which humans have achieved. This is true, but an important point/caveat here is that the evolution of ‘(relatively) advanced cultural and societal complexity’ in prehistoric times was not always contingent upon agriculture; agriculture often did lead to societal complexity, but humans could rise in societal complexity and experience significant cultural evolution without it – there were sedentary populations of some size and organizational complexity living in communities without what we usually conceptualize as agriculture (viz farming or pastoralism), e.g. in areas well-endowed with natural resources such as those near major lakes or coasts full of fish. To take one example (again from Scarre et al.), “agriculture was not a necessary prerequisite for the emergence of chiefdoms in the Southeast [North America]” – another example would be the “longstanding “Maritime Hypothesis” […] which proposes […] that maritime resources sustained population growth and the rise of sedentary earthwork-building communities” along the Pacific coast of South America during prehistoric times. There were mound builders in pre-agricultural North America as well, see e.g. this and this.

It’s worth remembering when thinking about human societies which existed especially during transitional phases – which may include many different time periods, depending on which part of the world you’re looking at – where people were starting to use agriculture but perhaps hadn’t really gotten the hang of it yet, that hunter-gatherer groups occasionally simply outcompeted farmers at the local level because some places just plain aren’t very good places to engage in agriculture, meaning that the ‘cultural victory’ of agriculturalists was by no means universal or a given at the local level, even if it’s very easy to convince yourself otherwise if you don’t know very much about these aspects of human development. Sometimes new (‘cultural’) inventions, like irrigation systems, could turn the tide in situations and geographic localities where agricultural food procurement strategies were at a disadvantage, but occasionally even that wasn’t enough.

Food production practices are/were key to societal complexity, because in order to get complexity you need to produce enough ‘excess food’ for some people to be free to engage themselves in non-food-production/procuring-activities, but another related point is that how to actually categorize and delineate various prehistoric food production practices is not always completely obvious. Food production undertaken by humans can take on multiple forms, and sometimes an ‘agriculture’ vs ‘hunter-gatherers’ dichotomic conceptualization of the issues may make you overlook important details due to ‘misclassification’ or similar problems; to take a couple of examples, some prehistoric sedentary societies based on fishing were as mentioned more or less stable food producing societies, and on a different note the cultural practices of (mobile) pastoralist societies often shared some social dimensions with hunter-gatherer societies that e.g. sedentary rice farming societies did not. Worth keeping in mind in this context is also that present-day hunter-gatherer societies still in existence often do not well reflect the cultural aspects of hunter-gatherer societies which existed in the far past, meaning that you need to be very careful about which inferences you make and what you base them on.

An aspect really important to keep in mind in general when thinking about the Holocene ‘post-agricultural period’ of human development is that the cultural development which took place in agricultural societies did not take place in a vacuum. Agriculturalists interacted with hunter-gatherers, farmers interacted with pastoralists, different e.g. geographic (mountains, seas) and biological constraints (malaria, horses) shaped human development in all kinds of ways. Boyd and Richerson do talk about this in the book, but I figured I should as well in this post. One thing to note is that in some areas agricultural practices spread much faster than in others for reasons having nothing to do with ‘the type’ of people who were doing these things, for example due to reasons of physical geography or other environmental constraints or the lack of such, and both the speed and manner of adoption likely had important (and varied) cultural ramifications. These things had genetic ramifications as well; areas where agricultural spread was particularly easy saw population growth other areas did not. Climate and climatic variation post-adoption incidentally naturally had important cultural ramifications as well – for example looking over the (pre)history of pre-colonial South America, it’s obvious that climate here was a key parameter with a huge impact on ‘the rise and fall of civilizations’.

There were multiple ways for agriculture to spread, from pure displacement to pure local adoption, as well as any combination in between, and how it proceeded varied with geography and probably a lot of other stuff as well. Some places and times the optimal type of agriculture was variable over time; which didn’t just mean that it made sense for farming societies to diversify and rely on more than one crop with different responses to e.g. drought, but also that climate change sometimes caused people to switch away from farming and towards pastoralism in bad periods – a good example of the latter is Peru during the Late Intermediate Period, where it is clear that “intensification of pastoralism was an important respone to drought” (see Moseley, p.246). Aspects such as climate have certainly had various important cultural as well as genetic impacts around the globe, e.g. on cultural transmission patterns at the regional level even during the ‘post-agricultural’ period. I mentioned interaction patterns – themselves a result of cultural dynamics, but also a driver of them – between sedentary farming societies and more mobile hunter-gatherers or pastoralists above, and perhaps I should say a little more about this kind of stuff because people may not be clear on precisely what I’m getting at there. It seems clear that in some areas division of labour dynamics played an important role in explaining and shaping cultural evolution; for a great account of these aspects of cultural dynamics and evolution in mountainous terrains and their surrounding areas, I again refer to Moseley’s account here. Inhabitants of sedentary farming societies didn’t move around very much, so things which were far away from them were things they’d often be willing to trade with more mobile human groupings. From one point of view you have a type of (modified) core-periphery model where the people from the core produced ‘excess’ food, and/or things which the people living in the core area who did not have to work on food procurement could come up with, which they then traded for other stuff, e.g. various natural resources located elsewhere (metals and wood are classic examples), with people who lived on the periphery. People looking at these things today without knowing anything about how such interaction patterns looked like may, I think, have a tendency to think of mobile hunter-gatherer groups as the morons who were left behind in this story and the pastoralists as more ‘primitive’ than the farmers, but I don’t really think that’s necessarily how it was – sometimes quite neat systems of exchange benefited both groups and were arguably by themselves important drivers of ‘cultural progress’, in the sense that they enabled and facilitated increased social complexity in the societies engaged in such systems. Of course peaceful interaction patterns were not the only ones which were explored.