Ape cultures do not require behavior copying
While culture is widespread in the animal kingdom, human culture has been claimed to be special due to being cumulative. It is currently debated which cognitive abilities support cumulative culture, but behavioural form copying is one of the main abilities proposed. One important source of contention is the presence or absence of behaviour copying in our closest living relatives, non-human great apes (apes) – especially given that their behaviour does not show clear signs of cumulation. Those who claim that apes copy behaviour often base this claim on the existence of stable ape cultures in the wild. We developed an individual-based model to test whether ape cultural patterns can emerge in absence of any behaviour copying, when only allowing for a well-supported alternative social learning mechanism, socially mediated reinnovation, where only the frequency of reinnovation is under social influence, but the form of the behaviour is not. Our model reflects wild ape life conditions, including physiological and behavioural needs, demographic and spatial features, and possible genetic and ecological variation between populations. Our results show that, under a wide range of values of parameters, we can reproduce the defining features of wild ape cultural patterns. Overall, our results show that ape cultures can emerge and stabilise without behaviour copying. Ape cultures do not show the signatures of behaviour copying abilities, lending support to the notion that behaviour copying is, among apes, unique in the human lineage. It therefore remains an open question when and why behaviour copying evolved in hominins.Competing Interest StatementThe authors have declared no competing interest.View Full Text