(p. 553) Cultural Evolution
If there is anything that sets humans apart from other animals, it has to be culture. Although we can point to behaviour that meets the definition of culture in many other species (see Plotkin, Section I; van Schaik, Section II), none the less the reality is that no animal comes close to producing the kinds of ‘higher culture’—literature, art, music, religion, philosophy or even science—that we find in modern humans. Studies of animal culture allow us to point to the origins of this unique human capacity, its phylogenetic history, but we are still left with the puzzle of explaining why it should have developed to such a remarkable extent in just one lineage of primates.
There are several separate issues here. First, it is perhaps obvious that most cultural activities are based on social learning (imitation of those with whom one lives or comes into contact, as well as that learned through instruction). The human capacity for imitation (and, in particular, the human child's capacity for imitation) is really quite extraordinary by the standards of more conventional animals. So we have a cognitive capacity to explain. But imitation on that scale can result in the imitator giving up his/her own interests in order to copy someone else's behaviour—in effect, behaving altruistically. Hence, there is a substantive question about why such high levels of behavioural altruism should be so common. Most of the literature on cultural evolution probably implicitly assumes that imitation is good for you (and hence your fitness) because it allows you to acquire knowledge more quickly about how to behave than could be done by individual trial and error. It need not always be so, of course. Henrich and McElreath explore this issue.
Second, there are questions to be asked about the processes involved and how they work in a Darwinian world dominated by genetic mechanisms of inheritance. It is clear that the dynamics of gene—culture evolution can be very complex, as McElreath and Henrich show. But there have been questions about just what is involved in the processes of cultural learning. Dawkins (1975) famously coined the term meme to refer to the cultural equivalent of gene in the processes of cultural transmission—a term that has not been without its problems, as Aunger points out. However, while recognizing that the term does have problems, we do need a generic label for whatever it is that is being culturally transmitted. For the moment, meme is probably the best we have.
Third, given that culture has a general function, we still need to ask how some of the more peculiar forms of culture maximize fitness. Just what functions do music or literature serve? Are they, as Pinker (1997) famously asserted, mere cheesecake—froth on the evolutionary seascape? The answer simply has to be “no”. As a rule of thumb, evolutionary biologists would insist that anything on which individuals lavish so much time, energy and (in our case) money must have a function. The mistake has probably (p. 554) been to think in terms of fitness as it reflects an individual's immediate abilities to survive or reproduce. It probably is true to say that song and dance has little effect on anyone's ability to survive, though one might argue with Miller (2000) that the abilities to sing or dance do have genuinely beneficial effects on one's opportunities to mate (with obvious and very real consequences for fitness). But there are other reasons why culture might be important, and these hark back to the ideas about multi-level selection that Wilson discusses in his contribution to this volume (see also Dunbar et al., 2005). When a species is as dependent on cooperation in social groups as humans are, forces that bond the individuals in those groups and enhance their cooperativeness become essential. Many aspects of ‘high’ culture, from story-telling to dance to religion, may be as important in creating that sense of groupishness as more conventional mechanisms like altruistic punishment (discussed by Gintis et al.) and cheat detection mechanisms (Cosmides, 1989). And, of course, all of these are dependent on another recent human trait—language (which Kirby addresses).
Fourth, we can ask when culture in this advanced form first evolved. Archaeologists have, of course, concerned themselves a great deal with just this question, though they have largely confined themselves to what is termed ‘material culture’, the physical forms that human cultural activity can take (stone or bone, occasionally wooden tools and other functional objects, artwork like Venus statues, and cave paintings). While there are important issues of timing that obviously bear on whether culture is uniquely human or shared with other animals, the archaeological record can, as Shennan points out, tell us a great deal more about the pace and process of cultural evolution than will ever be possible from observing living human populations. A closer integration between archaeologists and evolutionary psychologists (in the broad sense we use here) is long overdue.
We have mentioned music and literature in passing in this discussion, but it is worth highlighting the fact that these are two areas of human culture that are (i) of immense social importance, (ii) virtually unstudied from an evolutionary perspective and (iii) fascinating in their own right in terms of the cognitive capacities on which they depend. Carroll and Cross provide comprehensive reviews of these two topics, but it is clear that there are many layers of explanation that have not yet been tapped. The capacity to deal with imagined worlds is not merely cognitively very demanding (Barrett et al., 2000; Dunbar et al., 2005), but clearly fundamentally important to many aspects of human social life. Much the same can be said of religion, another important force for binding social groups. None the less, despite the centrality of religion as a topic in socio-cultural anthropology, evolutionary anthropologists and evolutionary psychologists have been very slow indeed to give it any attention. Bulbulia takes up this particular challenge in a very comprehensive review of recent work. Culture, and the capacity for culture, is in many ways the single most important problem in human evolutionary psychology.
Barrett, L., Dunbar, R. I. M. and Lycett, J. E. (2000) Human Evolutionary Psychology. Palgrave/Macmillan, Basingstoke and Princeton University Press, Princeton.
Cosmides, L. (1989) The logic of social exchange: has natural selection shaped how humans reason? Studies with the Wason selection task. Cognition, 31: 187–276.
Dawkins, R. (1975) The Selfish Gene. Oxford University Press, Oxford.
Dunbar, R. I. M., Barrett, L. and Lycett, J. E. (2005) Evolutionary Psychology: a beginner's guide. One World, Oxford.
Miller, G. (2000) The Mating Mind. Heinemann, London.
Pinker, S. (1997) How the Mind Works. Penguin, Harmondsworth.