When natural selection favors imitation of parents

It is commonly assumed that parents are important sources of socially learned behavior and beliefs. However, the empirical evidence that parents are cultural models is ambiguous, and debates continue over their importance. A formal theory that examines the evolution of psychological tendencies to imitate parents (vertical transmission) and to imitate non-parent adults (oblique transmission) in stochastic fluctuating environments points to forces that sometimes make vertical transmission adaptive, but oblique transmission recovers more quickly from rapid environmental change. These results suggest that neither mode of transmission should be expected to dominate the other across all domains. Vertical transmission may be preferred when (1) learned behavior affects fertility rather than survival to adulthood, (2) the relevant environment is stable, or (3) selection is strong. For those interested in the evolution of social learning in diverse taxa, these models provide predictions for use in comparative studies.