How cultural input shapes the development of idealized biological prototypes.

Young children in the U.S. tend to hold narrow, idealized prototypes for animal and social categories, focusing on ideas about how categories should be and ignoring category variability. The current studies (N = 281) tested how children's reliance on idealized prototypes might be shaped by adults' communication of common essentialist and teleological biases. In Study 1, 7- to 8-year-old U.S. children viewed more average members of novel animal categories as prototypical when they heard a teacher correct a generic statement about a characteristic feature and highlight how varied features serve varied functions. In Study 2, explanations about varied functions alone explained this effect for novel animals, with mixed effects for familiar animals; there was no additive effect of correcting generic language. Children in Study 2 also expected functionally ideal features to be more frequent among category members, suggesting that idealized prototypes reflect mistaken assumptions that category members homogeneously share ideal features. Children in Study 2 did not explicitly disapprove of nonconformity, suggesting that idealized prototypes do not reflect an inability to dissociate how things are from how they should be. Together, these results support the proposal that U.S. children's idealized prototypes are shaped by common conceptual biases perpetuated by cultural input.