The relationship between childhood exploration and population-level innovation in cultural evolution

The societal effects of children's learning in cultural evolution have been underexplored. Here, we investigate using agent-based models how a propensity for early exploration in childhood contributes to cultural adaptation and the evolution of long human childhood. Using a complex cultural task, we implemented a two-stage strategy for exploring this space-children explore broadly, and are more likely to learn new behaviours, while adults exploit behaviours already known, incrementally improving them. We found that populations that followed this two-stage strategy achieved higher payoffs in the long term than populations using the two exploration strategies in a random order. Our models point at a 'just right' length of childhood-neither too long, nor too short-allowing individuals enough time to explore before exploiting what they learned. Social learning increased payoffs when agents could copy individuals of a variety of ages, but reduced the benefit of early exploration. Payoffs decreased under environmental change, especially for long childhoods, because adults did not have enough time to recover between bouts of change.