Peter J. Richerson and Robert Boyd, Not by Genes Alone: How Culture Transformed Human Evolution

Abstract

When I read this book's predecessor, Culture and the Evolutionary Process, not long after it came out 20 years ago, it seemed to me to offer a new and more productive future for my discipline, archaeology. There were many features that were attractive but one of the most refreshing was its lack of dogmatism. Like many other humanities and social science disciplines, in the mid 1980s archaeology, in Britain at least, was going through a period of major upheaval. In the case of archaeology the so-called processual approach that had been pioneered by authors such as Lewis Binford in the 1960s, with its emphasis on culture as adaptation and its rejection of history, was being challenged by views that emphasised the meaning of artefacts rather than their function, and cul-tural uniqueness arising from specific histories rather than universal adaptive processes. You had to choose one camp or the other; there was no room for fence-sitting. The evolutionary approach of dual inheritance theory advocated by Boyd and Richerson rejected this dilemma. Adaptation was important but so were specific histories. It could not merely be assumed that adaptive problems called into existence their own solutions. The dynamics of culture itself were important. Moreover, the very features of human culture that made it adaptive also opened up the possibility of maladaptive developments. If one accepted this perspective, establishing the importance of adaptive payoffs or the specifics of particular histories in understanding patterning in the archae-ological record was not a matter of making a dogmatic commitment a priori but something to be elucidated in particular cases as a result of empirical work. However, this was not the only area of archaeology were dogmatism lurked. Dunnell (1980) had published a paper which rightly rejected the prevailing cultural evolutionism in archaeology, focussed on describing and explaining long-term change in social complexity, or, in more 19th century terms, the road from Savagery to Civilisation. He argued instead that only a Darwinian characterisation of the nature of evolution offered any hope of explaining the past as opposed to tendentiously describing it. For Dunnell this meant only Biology and Philosophy (2008) 23:293–299 Ó Springer 2006 DOI 10.1007/s10539-005-9007-5 two possibilities. Those artefacts, or attributes of artefacts, that were functional were aspects of the human phenotype whose variation affected the probability of survival and/or reproductive success of those that used them. Their fre-quency varied over time in response to variations in the survival and repro-ductive success of their makers and users. Thus, for example, the practice of tempering ceramic cooking vessels with material that gave them greater heat conductivity and resistance in boiling food spread as a practice in the mid-west because those individuals who adopted it produced more offspring than those who tempered their vessels with other materials. On the other hand, there were attributes of artefacts that did not have a function and were therefore not under selection (Dunnell 1978). These included features like the decoration on pottery in Dunnell's view and the process relevant to changes in their frequency was drift, random variations in the frequency with which they were copied. The two types of attribute were qualitatively absolutely distinct. Boyd and Richerson's framework undermined this dogmatism too. Instead of an absolute contrast between natural selection and drift, both beyond human control and awareness, they proposed a series of subtle processes designed to capture what was distinctive about cultural as opposed to genetic transmission. Important among these were their so-called 'decision-making biases', with their implication that what people decide to do in their day-to-day lives, not always but sometimes consciously, has significant evolutionary effects. Moreover, they explained why, in many if not most circumstances, following what other people already do, as opposed to making your own trial-and-error decisions, pays off, thus ensuring that the cultural inheritance system continues. Central to demonstrating the cogency of the approach developed in Culture and the Evolutionary Process, and the specific outcomes of the novel processes that were claimed to be important, was the methodology of mathematical modelling. Words are all very well but only mathematical modelling and computer simulation can tell you what the outcome will really be when a certain process is repeated over and over again. While such models and methods hold no fear for economists, they are alien to the vast majority of anthropologists and archaeologists. Those who come into these disciplines are mostly people who by virtue of ability, inclination and training find it very difficult to think in this sort of way. Thus, even for those in these fields who do not reject scientific approaches to culture and society out of hand, as the many post-modernists do, the implications of accepting the kind of mathematical approach laid out in Culture and the Evolutionary Process are disturbing, not least because, without the relevant mathematical skills, they are increasingly alienated and excluded from one of the most prestigious parts of their disci-pline: the development of new theory. They are in danger of becoming aca-demic hewers of wood and drawers of water. Of course, this is a situation that has emerged in many other disciplines as they have become more mathematical and the mathematicians and physicists start to look for the 'low-hanging fruit' that may easily be picked. 294