The teaching conundrum had been solved. Teaching evolves where the costs are outweighed by the inclusive fitness benefits that result from the tutor's relatives being more likely to acquire the valuable information. Teaching is not favored when the pupil can easily acquire the information on their own or through copying others. Nor is it favored when imparting traits that are difficult to learn, as teachers generally do not possess the information to pass on to their relatives. These restrictions typically lead to few circumstances under which teaching would be efficacious. Models that allow for cumulative cultural knowledge gain, however, suggest that teaching evolved in humans despite, rather than because of, our strong imitative capabilities, and primarily because cumulative culture renders otherwise difficult-to-acquire valuable information available to teach. The analyses suggest that human teaching and cumulative culture evolved together, through mutual reinforcement.
