University of Exeter

SCHOOL OF PSYCHOLOGY


PSY3004 Special Topics in Psychology/PSY6006 Advanced Seminars
Evolution of Human Behaviour Seminar Course

Animal cultures and cultural evolution:
Notes on the reading list


Health warning

These notes are being written because I cannot be at the session on 4th March 1999 to give my usual introductory talk on the reading.  I am writing them as I would usually give that talk, off the cuff and from memory, on the basis that some guidance is better than none.   I have not checked every reference, and it is possible that there are errors.  Please let me know of any.

Everything we have covered so far has been based on ideas that are strongly rooted in the genetic theory of natural selection.  Yet when we consider human behaviour, we see the influence of culture at every point.  How can we bring this into the analysis, while circumventing the unanswerable and stupid "nature-nurture question", which is not a question at all but an invitation to vacuous posing?  This session's readings offer two possible approaches, both of which seek to avoid the nature vs. nurture trap by recognizing that culture, like genetics,  is part of biology.

Basic issues

First, we need to recognize that humans are not unique in having cultural influences on our behaviour (though of course we are unique in the depth and all-pervading nature of that influence).  Cultural influence can be recognized in many other species, and this enables us to ask what the evolutionary preconditions for the formation of a culture may be. Bonner (1980) provides a summary of the facts of such "animal cultures", and Nishida (1987) gives more detail of their role in the life of primates, which is of course where we find some of the most striking and best known examples. The enormous role that culture plays in human life depends on cognitive abilities that  must be the product of natural selection: Wilson (1975) and Passingham (1982) introduce this issue, and Tooby and Cosmides (1992) discuss it at length.  A particular aspect of it, of course, is our ability to learn language, the chief vehicle for cultural transmission, and this is discussed by Pinker (1995); the chapter suggested for this week's reading, however, is more to do with the evolution of different languages, which brings us on to our second theme.

The second point is that we need to recognize that cultures, like species, are not "special creations", handed down capriciously or by God.  They are the products of historical processes, which are evolutionary at least in the sense that they are usually quite gradual.  In formulating his evolutionary theory of the origin of species, Darwin was influenced by the evolutionary theory of the origin of a primary element of culture, languages, which had been worked out by the philologists of the late 18th and early 19th century, studying how modern European languages had descended from earlier Germanic and Romance roots.  The exciting possibility that was raised by Dawkins (1976/1989, chapter 11) was that this kind of cultural evolution might actually obey the same rules as genetic evolution; in the context of sociobiology, this was a new idea, and Dawkins expressed it in a new way which makes this chapter one that everyone should read; but ideas rather like it had been circulating among evolutionary anthropologists such as White, Service and others for many decades.  It is not in doubt that cultures, and elements of culture, change into one another; what is questioned is whether the change is influenced by adaptiveness - whether there is any element of selection.  For many anthropologists, influenced by the dominant school of Franz Boas for whom culture was always autonomous from all external influences, the idea of selection operating at the cultural level is heresy.  The most influential exponent of the alternative view is Marvin Harris (e.g. 1979); his "Cultural materialism" is not the same as a sociobiological approach, but has strong affinities - he sees culture as at least strongly constrained by the material technology available to a society.

Following Dawkins' lead, other sociobiologists were quick to take up the challenge to integrate cultural factors into their thinking.  An early discussion is given by Durham (1978).  E. O. Wilson began a collaboration with an anthropologist, Charles Lumsden, and their introductory book, Lumsden & Wilson (1983) is an attempt to present their theory of gene-culture co-evolution, in which genetic and cultural selection are seen as interacting on and modifying each other, for a lay audience.

Evidence for cultural variation in animals

Celia Heyes (1993) is a penetrating and influential British comparative psychologist, and her sceptical analysis of the possibilities of social learning is essential reading if you are at risk of getting carried away by ideas about animal cultures.  Laland (1996) gives a more upbeat view.  Tomasello and Call (1997) focus on the primate evidence, setting it in the context of what we know about primate social learning.  Avital et al (1998) try to use cultural evolution theory to explain an enduring puzzle about primate social behaviour, the frequent adoption of orphaned young by unrelated adults.  The remaining readings in this section are particular examples of cultural transmission. Galef and Whiskin (1997) attempt to induce artificial cultures, about food preferences, in groups of rats.  The best studied cases of natural cultures involve song in passerine birds (the common "songbirds"), where the general rule seems to be that only a relatively simple template is laid down genetically, and individuals embellish this and are imitated by others, so that local dialects emerge. Krebs and Kroodsma (1980) provide an authoritative (but not simple) account of the phenomena, and Mundinger (1982) is an example of the technical detail required to draw sound conclusions in this area; West and King (1996) put the birdsong dialects literature into a more modern theoretical context - this may be a more digestible article for some tastes. Green (1975) studies a similar vocal cultural phenomenon in primates, and Huffman (1996) looks at the evidence for cultural transmission of manual skills in primates.

Adaptive nature of culturally determined behaviour

When we turn to look at the evolution of cultures and cultural trends, the key question is whether change is directed by some kind of selection.  A necessary (though not sufficient) condition for that hypothesis to be tenable is that behaviours that are clearly culturally influenced should be adaptive.  Readings in this section assess the evidence that this is so.  The chapter from Barash (1982) provides an early overview of the anthropological evidence, of course from a sociobiological perspective; Lefebvre and Giraldeau (1996) take a more theoretical look. Harris (1977) argues strongly that some well known examples of cultural trends are explicable in terms of nutritional and other needs, and in his book Cultural materialism(Harris, 1979) he integrates these examples into a theory.  The 1979 book is quite hard going, but students usually enjoy the 1977 book of essays (Harris has written others, too), which has a direct, approachable style not too often found among anthropologists.  Crook (1980) explores the possibility that cultural trends are adaptive in the context of his attempt to give a general account of the evolution of humans' unique cognitive qualities.  Alexander (1979) looks at the specific possibility that moral rules are adaptive.  But not everyone is persuaded. Aitchison (1981), one of the leading linguistics experts in the UK, robustly (and wittily) rejects the idea that language change is influenced by adaptive constraints.  Chagnon (1981), though sympathetic to sociobiology, gives an account of behaviour in a hunter-gatherer tribe that shows that simple adaptivity theory may be hard to apply to real examples of cultural change.  Finally, the article by Skinner (1969) gives an older view of what selection at the cultural level might mean, but one that has many resonances in more modern ideas, and is still worth thinking about.

Explicit sociobiology of human cultures

Finally some readings that have tried to apply the full weight of sociobiological ideas to cultural phenomena.  Lumsden and Wilson (1981) is a much weightier book than Promethean fire: it works out the technical ideas that Lumsden and Wilson were trying to present to a popular audience in the simpler book.  Barkow (1992) makes the case for an evolutionary psychology of culture.  Winterhalder and Smith (1981) are anthropologists who try to apply not sociobiology exactly, but the kind of optimal foraging theory popular in behavioural ecology, to the behaviour of hunter-gatherers; this does not go down well with all anthropologists, as the review of their book by Martin (1983) shows.  The articles by Hayden (1981) and Harako (1981) are in a somewhat similar line, though more informed by primatology.  Finally Hinde and Barden (1985) bring us full circle by providing us with a playful but direct application of meme theory to a particular small-scale cultural phenomenon.

Questions for discussion

  1. Do the animal data support Dawkins' meme theory of cultural evolution?  The "meme" idea is highly attractive.  But if it is to be more than an intellectual plaything, it has to be shown to be able to do some serious work.  The easiest field for it to work in would, presumably, be the relatively restricted area of cultural inheritance of animal behaviours.  How do you feel it fares there?
  2. On the whole, are culturally determined behaviours adaptive?  A simple little question, which merely requires you to settle the key debates of 20th century social anthropology...  But within the limits of what you can read, this question warns you not to get carried away by single examples, but to weigh one phenomenon with another and see what generalizations you can draw, at least from your own reading.
  3. If adaptiveness does not determine what cultures and/or culturally determined traits survive, what are the true selective forces acting on cultures? Are they different in humans and in other animals?  It is all very well for anthropologists, philologists and others to reject the idea of adaptive constraint on cultural change.  But if not this hypothesis, what hypothesis (to distort Herbert Spencer yet again)?  Among the possibilities are randomness (the hypothesis of despair), politico-economic power (everyone speaks English because of the power of the Royal Navy in past centuries and American capitalism in this)... and what else?  The animal cultures data form a valuable restraint on theorizing in this area.
  4. Could cultural evolution support group selection?  In the context of our course, this is the $64,000 question.  In genetic evolution, the condition for group selection is rarely if ever going to be met: it is that groups should face extinction faster than the individuals that make them up.  But in cultural evolution, with appropriate definitions of "cultural group" and "cultural extinction", it might just happen quite often.  All sorts of interesting possibilities are then opened up - for an example an explanation of why cultural rules generally require higher levels of altruism than we are genetically predisposed to show.

Stephen Lea

University of Exeter
Department of Psychology
Washington Singer Laboratories
Exeter EX4 4QG
United Kingdom
Tel +44 1392 264626
Fax +44 1392 264623


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Document produced 19th July 1999