How Darwinian is Cultural Evolution?


Nicolas Claidière, Thomas C. Scott-Phillips, and Dan Sperber over at the Philosophical Transactions of the Royal Society (image via Wikimedia Commons):


Darwin-inspired population thinking suggests approaching culture as a population of items of different types, whose relative frequencies may change over time. Three nested subtypes of populational models can be distinguished: evolutionary, selectional and replicative. Substantial progress has been made in the study of cultural evolution by modelling it within the selectional frame. This progress has involved idealizing away from phenomena that may be critical to an adequate understanding of culture and cultural evolution, particularly the constructive aspect of the mechanisms of cultural transmission. Taking these aspects into account, we describe cultural evolution in terms of cultural attraction, which is populational and evolutionary, but only selectional under certain circumstances. As such, in order to model cultural evolution, we must not simply adjust existing replicative or selectional models but we should rathergeneralize them, so that, just as replicator-based selection is one form that Darwinian selection can take, selection itself is one of several different forms that attraction can take. We present an elementary formalization of the idea of cultural attraction.

1. Population thinking applied to culture

In the past 50 years, there have been major advances in the study of cultural evolution inspired by ideas and models from evolutionary biology. Modelling cultural evolution involves, as it would for any complex phenomenon, making simplifying assumptions; many factors have to be idealized away. Each particular idealization involves a distinct trade-off between gaining clarity and insight into hopefully major dimensions of the phenomenon and neglecting presumably less important dimensions. Should one look for the best possible idealization? There may not be one. Different sets of simplifying assumptions may each uniquely yield worthwhile insights. In this article, we briefly consider some of the simplifications that are made in current models of cultural evolution and then suggest how important dimensions of the phenomenon that have been idealized away might profitably be introduced in a novel approach that we see as complementary rather than as alternative to current approaches. All these approaches, including the one we are advocating, are Darwinian, but in different ways that are worth spelling out.

Much clarity has been gained by drawing on the analogy between cultural and biological evolution (an analogy suggested by Darwin himself: ‘The formation of different languages and of distinct species, and the proofs that both have been developed through a gradual process, are curiously parallel’. This has made it possible to draw inspiration from formal methods in population genetics with appropriate adjustments and innovations. Of course, the analogy with biological evolution is not perfect. For example, variations in human cultural evolution are often intentionally produced in the pursuit of specific goals and hence are much less random than in the biological case.

More here.