A revival of functionalism?
Human Culture Subject To Natural Selection, Study Shows:
The Stanford team studied reports of canoe designs from 11 Oceanic island cultures. They evaluated 96 functional features (such as how the hull was constructed or the way outriggers were attached) that could contribute to the seaworthiness of the canoes and thus have a bearing on fishing success or survival during migration or warfare.They also evaluated 38 decorative or symbolic features (such as the types of carved or painted designs). They analyzed mathematically the rates of change for the two groups of canoe design traits from island group to island group. Statistical test results showed clearly that the functional canoe design elements changed more slowly over time, indicating that natural selection could be weeding out inferior new designs. This cultural analysis is similar to analyses of the human genome that have been successful in finding which genes are under selection.
The study is coming out on the 19th in PNAS (so that means it will show up on the website at some time after that date). As most of you know in the 1960s the neutral theory of molecular evolution emerged in response to the finding that there was a great deal of extant genetic variation on allozyme loci (OK, to be fair neutralist ideas predate the empirical results; but I think it is clear that those results made the model intellectually far more compelling). Prior to this there were two broad schools of evolutionary genetic thought; one group accepted that there would be low levels of polymorphism due to balancing selection, and another assumed that there would be little to no polymorphism because of selective constraint. No matter the rearguard attempts by the likes of Richard Dawkins to argue that molecular variation “doesn’t count,” I think the neutralist (or nearly neutralist) insights are important in giving us a better understanding of the nature of evolutionary dynamics on the genomic scale. In The Origins of Genome Architecture Mike Lynch argues that low effective population sizes have had a strong role in shaping the character of genomic variation in more complex organisms. In other words, we are all non-adaptationists now!
What does any of that have to do with the paper above? Peter Richerson & Robert Boyd, L. L. Cavalli-Sforza and Marcus Feldman and E. O. Wilson & Charles Lumsden have all attempted to show how evolutionary processes are relevant to our understanding of human soceties. Unfortunately, as L. L. Cavalli-Sforza observes, cultural anthropologists are less interested in understanding humans as opposed to interpreting them. Formal frameworks to accompany the mass of empirical observations are simply neglected or seen as unnecessary. This is an unfortunate overreaction to the hubris of earlier generations of anthropologists who attempted to shoehorn all human variety into a set of functional adaptations. Instead of a happy medium where skepticism is balanced with empiricism and rationalism, anthropology has swung from a total lack of critical analysis toward one where positive assertions are eschewed on principle (unless, of course, those assertions are directed toward Western culture).
In Darwin’s Cathedral David Sloan Wilson tries to make an argument for resurrecting a functional understanding of cultural traits as adaptations. I think that this sort of work is hard-going, at least beyond the level of triviality (e.g., the rationales for why the Inuit dress the way they do is rather straightforward). That is because “culture” is a very broad and ill-defined term and the selective pressures are myriad; the environment, the social matrix and the correlations with other traits are all critical. Wilson’s methodology in Darwin’s Cathedral was to use case studies; I don’t think that that will cut it. Rather, massive surveys of collected data tested via statistical methods are probably more useful in extracting out the adaptive trends as a function of time and space. I do not, for example, think it is a coincidence that over the last 2,500 years all the complex cultural traditions on the World Island became associated with what we would call “Higher Religions,” roughly, the fusion of supernaturalism with philosophy and institutional structures. But were these parallel developments a function of the specific adaptive needs of these complex societies? Or where they perhaps inevitable byproducts of the sufficient intersections of modal human psychology with the rise of the novelties of mass post-tribal society?
These are big complex questions. I think that are certainly functionally significant cultural adaptations. That being said, I am not sure sure that they are responsible for the preponderance of between cultural variation. To go back to the example of Higher Religions, I think one can plausibly argue that some sort of synthesis between intuitively appealing extant supernaturalism with the intellectual & institutional abstracting tendencies of complex societies made them inevitable, necessary perhaps. Societies which were united by a common religious ethos may very well have been more fit than societies still characterized by a welter of tribal gods uncomfortably corralled under one political dispensation (though the dynamic might usually have been played out within an intrasocietal context; e.g., the introduction of Buddhism to Tibet and Japan by a particular faction at court and the subsequent nativist reaction with failed). But the specific nature of the Higher Religions may very well be arbitrary, neutral so to speak, because like a synonymous substitution they have no functional significance.
Obviously the paper above targets the law hanging fruit. Engineering is not contingent upon the caprice of human social dynamics; it works, or it doesn’t, by the grace of Mother Nature. But it’s a start, as it is a reality check upon those who would argue that the full sample space of cultural possibilities are theoretically at play, and equally likely. The next step is to start examining traits not so strongly constrained by physical conditions.
Labels: culture, Human Evolution
It’s more helpful to view cultural transmission and evolution not as natural selection that affects adaptation of humans to their environment, but instead as the spread of contagious diseases among a host population. The idea goes back awhile, at least to the late ’60s, and there’s a fair amount of good data showing this. Usually the model is some variation on the theme of S-I-R models of disease.
This accounts for why some aspects of culture don’t serve any adaptive purpose in humans, or may affect us negatively, while other aspects might help us. Germs can be good, bad, or neutral to our fitness. In the case of functional parts of boat design, we could say that these were under tighter functional constraint of the culture-germ — to spread throughout most of the host population, it has to obey constraints just as much as a germ that worms its way through the gastrointestinal tract in order to get to the liver or kidney or something.
You can also look at it as a learning curve in a community of skilled craftsmen. Boatbuilders and navigators were the most highly honored men in these societies, and they had a lot of autonomy in a tightly knit tribal society where most were closely restricted by kinship and ritual obligations.
In a way I think you have this backward. One problem of evolutions has been “Why do organisms seem as though they were designed, even though they were not?” But the boats were designed, and it’s quite possible that changes in design were deliberate experiments that proved successful. (Many pre-modern peoples were technically rational and highly skilled on topics of concern to them — Eskimos in many ways, Mongols on warfare, horses, and cold-weather survival).
Conceptualizing evolution as a learning curve can be illuminating, just as conceptualizing learning as eveolution might be. Donald Campbell’s “Evolutionary Epistemology” develops “blind variation and selective retention” into many different fields. I think that it can be developed into a very general principle.
Ev epist
Campbell
Ev Epist II
For some reason, you keep not mentioning what I think is the most important recent development in this phenomenon: the replacement of the supernatural with the political. If this isn’t a functional mutation, I don’t know what the heck is.
I mean, dear god, look at Obama. Could it be more blatant?
mencius, i’m sorry that i don’t anticipate your genius!
It’s more helpful to view cultural transmission and evolution not as natural selection that affects adaptation of humans to their environment, but instead as the spread of contagious diseases among a host population. The idea goes back awhile, at least to the late ’60s, and there’s a fair amount of good data showing this. Usually the model is some variation on the theme of S-I-R models of disease.
sperberesque epidemiology of ideas?
Mencius, come on. That’s a meme, in the contemporary sense of “something dumb that proliferates virally”.
I haven’t read Sperber on the epidemiology of ideas, but Bartholomew wrote about SIR models of culture (really “spread of information,” but that’s the same) in his book on stochastic models in culture in the late ’60s. Cavalli-Sforza and Feldman bring up SIR models in their culture book, but don’t really go anywhere with it. A group including Boyd and Richerson have developed a model called something like “random copying” that is equivalent to an epidemic disease model, and Watts &…someone developed a social contagion model in J of Theoret Bio a few years ago.
What I object to with the epidemic disease model, and to an extent the evolutionary model, is that it excludes the active learning involved in the case in question. Social science has a tendency to want to make people into objects (patients) rather than subjects (agents), and sometimes that’s the way to go, but in this case I think that active experimentation and testing by conscious agents is an important factor. That doesn’t necessarily mean that epidemiological or evolutionary models are completely irrelevant, but I’d guess is that the frequency and viability of mutations is increased by the conscious creative factor.
assman, yeah, i know a lot of those workers (i know boyd & rich’s and cavalli-sforza & feldman’s books). the sort of functionalism referred to here seems like a subset of the epidemiological models which are adapting in large part to human psychology and sociology. i’m generally skeptical of functional adaptations to exogenous parameters. e.g., hindus are vegetarian because eating meat is not efficient in terms of maximizing the utilization of agricultural resources. but it doesn’t seem like all these examples would be false. since i think i that these adaptations to exogenous parameters are a relatively small number (with many variations on a few common themes) it might be best to start from them and work background (assume other aspects of culture are epidemiological and evoked).
but in this case I think that active experimentation and testing by conscious agents is an important factor.
right, but cognitive science tells us that we’re biased in terms of what and how quickly we can learn something. from what i remember that’s worked into some of the models.
But canoe-making an apprenticeship system, and the apprentices were basically being trained, rather than deciding what they thought, or happening to pick something up that was in the air. The successful builders would presumably have more apprentices, and if they were successful because of a deliberate innovation, the innovation would be passed on.
john, check out some of joe henrich’s work….
http://www.psych.ubc.ca/~henrich/home.html
covers the type of stuff you’re talking about.
The paper itself seems interesting but the discussion in the news article reminded me of some of the papers coming out of, say, the Santa Fe Institute in the 90s during the complex systems and game theory fad.
The paper itself seems interesting but the discussion in the news article reminded me of some of the papers coming out of, say, the Santa Fe Institute in the 90s during the complex systems and game theory fad.
yeah. i’m definitely going to look at the paper closely. unfortunately the science of culture is mostly about false positives….
The trouble is that when you’re doing epidemiology, you look at the actual channels through which the pest travels. Eg, bathhouses for HIV, or whatever.
But when people talk about religious and political memes, they tend to assume the ideas are just wafting through the air in an unstructured, diffuse “marketplace.” Au contraire. To paraphrase Richard Weaver: ideas have bathhouses.
In fact, I think we’re in one right now…