CRITICAL POINTS IN CURRENT THEORY OF CONFORMIST SOCIAL LEARNING

Existing mathematical models suggest that gene-culture co- evolution favours a conformist bias in social learning, that is a psycho- logical mechanism to preferentially acquire the most common cultural variants. Here we show that this conclusion relies on specific assump- tions that seem unrealistic, such as that all cultural variants are known to every individual. We present two models that remove these assumptions, showing that: 1) the rate of cultural evolution and the adaptive value of culture are higher in a population in which individuals picks cultural variants at random (Random strategy) rather than picking the most com- mon one (Conform strategy); 2) in genetic evolution the Random strategy outcompetes the Conform strategy, unless cultural evolution is very slow, in which case Conform and Random usually coexist; 3) the individuals’ ability to evaluate cultural variants is a more important determinant of the adaptive value of culture than frequency-based choice strategies. We also review existing empirical literature and game-theoretic arguments for conformity, finding neither strong empirical evidence nor a strong theoretical expectation for a general conformist bias. Our own vignette study of social learning shows that people may indeed use different so- cial learning strategies depending on context.