Cultural evolution, social ratcheting and the evolution of human division of labour

Cultural ratcheting describes how cultural products become too complex for a naive individual to recreate from scratch. Using simulation models, we show that cumulative cultural evolution can produce a parallel social ratcheting, in which culturally specialised individuals and groups become irreversibly interdependent.

Social network structure spreads the cognitive cost of cultural production across specialists. Unlike earlier models that assume unlimited memory, we limit what each individual can remember to a fraction of the cultural repertoire — and find that this speeds up both cultural evolution and social differentiation. Cultural and social ratcheting may have been two linked outcomes of cultural evolution in the hominin lineage.