I am writing this in Frankfurt, where we have just concluded a week-long meeting on cultural evolution. I was hoping to write about it earlier, but this meeting has been so intense that I literally could not find a couple of hours to put my impressions on paper (or computer screen). The meeting was organized by Strüngmann Forum. There are no talks. Instead some participants write position papers that serve as a basis for discussions (mine was on the evolutionary transition from small-scale to large-scale societies, naturally). During a typical conference there are always talks that are less interesting, and that gives one the opportunity to write something, but not in this one.
Most discussions were within four subgroups, meeting separately, although there also was plenty of opportunity to attend other groups. My group focused on the evolution of small-scale and large-scale societies in humans. We had a developmental psychologist, primatologists, anthropologists, and modelers in the group. A really interesting and novel aspect for me was our focus on psychological predispositions (that are genetically determined), which made the transition from very small-scale societies of our putative ape ancestors to small-scale societies of humans (which are huge by comparison with other mammals, such as chimps or wolves). And then what role these psychological mechanisms played in the transition to large-scale societies. Basically, these predispositions were the building blocks that evolution used in constructing our societies
As an example, humans are primed to recognize norms (socially transmitted rules of behavior) by extracting the relevant information from observations of how other people behave. This ability appears very early in infants, but great apes don’t have it. And, of course, the norms and institutions are at the core of human sociality, both in small-scale and in large-scale societies. But not all of our behavioral predispositions played the same role at different phases of human evolution. For example, inequity aversion was a key enabler of cooperation in small-scale societies. On the other hand, it was a barrier for the transition to large-scale societies that evolution had to overcome. This is a very interesting subject, on which I have already touched earlier, and will need to return to it again.
Group 2 addressed the evolution of technology and science. Technology is a great case study of cultural evolution because it is relatively easy to trace how it develops (usually, in small increments and as a result of much blind variation). Group 3 discussed the evolution of language, our best example of gene-culture coevolution. As our ancestors began using vocalizations for communication, there was a very strong genetic evolution that remodeled our ability to produce sounds very precisely, and also our ability to distinguish speech patterns (for example, humans are extremely good at detecting accents). The evolution pressure was very strong, because those who could not express themselves well (and understand others well) would not get mates, lose out in negotiations, etc. Just think of the fact that in English the word ‘dumb’ is often used as a synonym for ‘stupid.’
Group 4 was devoted to the evolution of religion. This is the one I spent the most time with because I am very fascinated by the question of how religion, especially Axial religions, enabled the rise of really large societies. In fact, I am involved in a collaboration where we plan to add religious variables to our historical database of cultural evolution, which will enable us to test a variety of theories on the interrelations of organized religion and social complexity.
One thing that really struck me at this meeting is how far cultural evolution has progressed in the last decade or so. In particular, there was a great degree of consensus among the participants that cultural group selection is the only general mechanism for explaining how human sociality evolved that really has the logical coherence and empirical support. I already had this experience during our NIMBioS workshop in Knoxville, and there was very little overlap between the NIMBioS group and the Frankfurt group (about 45 people were in attendance here). There is really some kind of sea change occurring right now. It looks like cultural evolution is in phase transition from a marginal new discipline to a field that will establish the next paradigm of how we think about human nature and the nature of human societies.
I’ll have to deal with these fascinating issues in later blogs, because now I have to rush to the airport for my flight to Moscow, where I will probably not have a good e-mail connection. So I will resume blogging after I get back from Europe two weeks from now.
Interesting post. I had heard about this meeting from other participants. It sounds like a great forum and I wish I could have been there. I look forward to reading the results.
“there was a great degree of consensus among the participants that cultural group selection is the only general mechanism for explaining how human sociality evolved that really has the logical coherence and empirical support.”
I am sympathetic to cultural group selection (CGS hereafter), but I would just like to take issue with the proposition that CGS can explain how human sociality evolved, full stop. The problem is that CGS cannot explain how CGS itself came into being in humans, when there is no suggestion of it applying in other species.
It seems to me that CGS can explain about a third part of the explanandum (how human sociality evolved). What CGS is probably good at explaining is how small-scale societies were transformed into larger-scale societies. That seems to be the main focus of your research, so I am not surprised that you find CGS so interesting.
However, as an evolutionary developmental psychologist I am also interested in more ‘micro-level’ cooperation processes. There are two earlier parts to the explanandum that I do not think CGS can explain, namely (1) how the kind of small-scale sociality that is characteristic of human hunter-gatherers (and that is already vastly more ‘advanced’ than that of chimps etc.) evolved; and (2) why CGS first took off so that these small-scale societies were transformed into larger-scale ones (after humans had been ‘stuck’ in small-scale societies for hundreds of thousands of years). I believe that kin selection (or some other form of inclusive fitness) is a possible explanation for (1), and that indirect reciprocity is a possible explanation for (2). It does not seem appropriate to go into the reasoning behind that at this point, but I will be happy to carry on the conversation here if you delve into these matters more deeply in later posts.
In any case, the details of the mechanisms involved are less important than the general principle that we should be seeking an *integrated* answer to the three parts of the explanandum. I hope that as cultural evolution matures as an area of inquiry, this type of integrated explanation will develop. Hopefully we will not fall into the trap of splitting into different camps, each with their favoured type of explanation, or that of alternating between favoured explanations as if they were fashion trends. As students of cultural evolution, we should be above that kind of thing!
Peter, thanks for the update on the Strüngmann Forum and the sea change that you are experiencing in the maturity and acceptance of cultural evolutionary theory. I hope that the energy coming out of meetings such as these can culminate in a way that creates momentum, such as a bi-annual global conference that would attract people from a multitude of fields.
Gordon, I’m sympathetic to your worry about diverging evolutionary explanations for human behavior, culture and society. While I share your concern, however, I disagree about the role and appropriate scope of application of cultural group selection (CGS). I am myself a student of cultural evolution as well, but I am sensitive to the important contributions that evolutionary psychologists such as yourself have made to understanding the heart of the culture-biology crucible that is the human mind.
The point that I would like to make is that the theory of CGS is highly consistent with mechanisms you mentioned (kin selection and reciprocity) for the evolution of early human sociality. Of course Peter didn’t get to lay out any detailed (and therefore critique-able) proposal, but, any complete explanation of the rise of modern society or modern human sociality which employs CGS is fundamentally and deeply compatible with, or even reliant on both kin selection and reciprocity. CGS is not an alternative to such mechanisms, but an additional set of factors which enhance the strength of selection due to them. Thus, cultural group selection would accelerate the evolution of human psychological predispositions for reciprocity, for instance, by elevating the importance of reciprocal relations within groups via selection on differential success of groups due to different capacities for, say reputation tracking. Please pardon me if this is obvious.
The challenge for folks like you and I is, I believe, to be very specific and clear about the action of individual mechanisms in our research, (reciprocity, drift, sexual selection), while at the same time keeping our eyes on the prize of a unified evolutionary theory of humanity past and present. Cultural group selection, as one name for the evolutionary amalgam of a entire host of social and biological mechanisms, is not a pretender to that throne, but a valid candidate for such a unified theory.
Reblogged this on Mind and Culture and commented:
Made a comment on Peter Turchin’s blog post about cultural group selection. I think he has done some fascinating work, and I am quite envious of the people at the Frankfurt meeting (some of whom are my friends) who got to meet him!
I should probably stop spamming this blog (sorry, I am new to WordPress and didn’t realise that rebloggin this with a comment would make a comment here) and give Peter a chance to reply, if he wants to.
I would just like to say though that I find your comments quite reassuring, Tim. There is also the argument that scientific progress is often made through different groups of people advocating conflicting paradigms. However, I still cannot see how the same general mechanism – cultural group selection – can explain both large-scale social and technological change combined with biological inertia over the last hundred thousand years or so, and large-scale biological changes combined with (presumed) social and technological inertia over the previous million years or so. For me it feels more natural to use CGS to explain the former change and more biological mechanisms to explain the latter. I realise that this needs a lot of fleshing out, though (which I haven’t published yet) so will leave it there for now.
Just as group selection’s arch rival is kin selection, so cultural group selection must compete with cultural kin selection.
How much time did your group spend dicussing cultural parental care and cultural kin recognition? Not too much I will wager. This means that most cultural evolution practitioners are still in the field’s pre-1964 phase – and that there is major disruption for its group selection enthusiasts coming down the turnpike.
Gordon, Rob Boyd and I imagine that the hominin lineage first evolved a fairly advanced capacity for culture for ordinary adaptive purposes. This might have included simple social rules. Cultural transmission includes mechanisms that will tend to build up variation between local groups. The most basic of these is that culture evolves faster than genes, meaning that the directional forces in cultural evolution are stronger relative to migration than in the genetic case. Selection might also favor innate systems for using this variation to improve ordinary fitness. For example we have build models where ethnic markers are used to help people not imitate people from other ecological situations who are likely to have the wrong cultural traits for one’s own environment. Such a mechanism will damp down effective migration rates. The greater between group differences compared to the genetic case might have made cultural group selection an effective force in some ancestral population whose propensities to cooperate were still quite limited.
This scenario is not necessarily correct, but it shows “how possibly” cultural group selection could have gotten started.
Sarah Hrdy in her recent book argues that cooperative breeding in some early population got a basic level of cooperative predispositions going before culture became important and that this served as a foundation for later events involving culture. Bernard Chapais in his recent book has a related idea. If a hominin lineage fairly deep in the past became pair bonded, patrilateral relatives could begin to contribute to cooperative breeding and other cooperative activities. In chimpanzee like societies, paternity certainty is too low to motivate fathers much less other patrilateral relative to do much helping.
Larger groups of cooperators would make a cultural system more effective by giving kids more individuals to learn from. At least when they are young, other ape kids are almost entirely with their mothers and have limited opportunity to interact with other adults. Thus, hominin cooperation might have moved beyond that of the last common ancestor with the other apes before culture became important. Or perhaps culturally transmitted social rules were already playing a role when cooperative breeding and patrilateral kinship were evolving.
Tim T, I think most evolutionists now agree that kin and group selection are the same thing. In the case of CGS, culture has the effect of creating a lot of similarity between people who are distantly related genetically. From the point of view of Hamilton’s Rule a rather large group of people can have high cultural relatedness. This is the CGS idea. You are right in the sense that we can imagine that CGS goes on at multiple levels. High degrees of cultural relatedness at the band scale may trump the evolution of cooperation at the tribal scale. High relatedness at the tribal scale may trump the evolution of cooperation at the national scale. Darwin had a sensible discussion of these issues in the Descent of Man. See the chapter On the Development of the Intellectual and Moral Faculties in Primeval and Civilized Times. Peter Turchin’s and Herb Gintis’ background papers for our meeting covered these issues in some detail. I like to think we’re past 1964! Most of us who work on CGS were either trained as evolutionary biologists or have familiarized ourselves with Hamilton and post Hamilton evolutionary theories of cooperation. There is a certain amount of controversy about CGS, but most of it is conducted at a pretty sophisticated level.
Thanks for your intervention, Pete: your comment all makes a great deal of sense to me. I also find it slightly embarrassing in that I have had Sarah Hrdy’s book on my shelf, almost unopened, for longer than I care to remember. So this has prompted me to get into it properly in the near future. I hadn’t actually heard of Bernard Chapais before, but that book looks fascinating – will buy it soon. As a social anthropologist (by bachelors degree) I have the strong suspicion that modelling of kinship relations may have been fundamental to human cognitive evolution.
Hi, Peter! While modern theories of kin and group selection make the same predictions, the frameworks have inspired different research programs – with kin selection being much more closely associated with interactions with close kin – such as parental care – which typically don’t make much of a showing in the literature on group selection. Indeed, group selection has been largely abandoned by mainstream evolutionary biology as being redundant, confusing and awkward. It’s mostly within the biologically-inspired social sciences that it continues to lead a zombie existence.
Kin selection overwhelmed group selection as the explanatory framework of choice for most purposes in the organic realm back in the 1970s. The only issue I see is when the same revolution will take place in the cultural realm.
No, kin selection has proven out in multiple species and research testing. Group selection has failed in all attempts to even define it. Cultural selection is without any empirical support or definition whatsoever – let alone predictability or testing.
At bottom this is all just naive and pop human exceptionalism. Ain’t no such thing.
There are actually a number of definitions of group selection – e.g. see: “Capturing the superorganism: a formal theory of group adaptation”. The problem has been less lack of definitions, than lack of consensus – though we started to see more consensus in around 2009 as the main proponents of group selection woke up / came around – or however you want to look at it. E.g. see papers like “Multilevel and kin selection in a connected world” – which date from that era.
You don’t seem familiar with the large literature on cultural evolution. Perhaps take a look before posting more on that topic.