Critical social learning: A solution to Rogers' paradox of non-adaptive culture

We expand Rogers’ (1988) game theoretical model of the evolution of social learning considering that 1) individual learning does not always pro- duce optimal behavior; 2) social learning is not always accurate. Further, we introduce a “critical social learning” strategy that tries to solve an adaptive problem first by social learning, and then by individual learning if socially acquired behavior proves unsatisfactory. This strategy is always superior to pure social learning and has typically higher fitness than pure individual learning, providing a solution to Rogers’ paradox of non-adaptive culture. Critical social learning is an evolutionarily stable strategy (ESS) unless cul- tural transmission is highly unfaithful, the environment highly variable or social learning much costlier than individual learning, and quite independent of the success rate of individual learning. We compare the model to empir- ical data on social learning and on spatial variation in primate cultures, and list three requirements for adaptive culture.