In order for children to understand and reason about the world in an adult-like fashion, they need to learn that conceptual categories are organized in a hierarchical fashion (e.g., a dog is also an animal). While children learn from their first-hand observation of the world, social knowledge transmission via language can also play an important…

A new series of studies on adults' and infants' perception of phonetic "prototypes," exceptionally good instances of phonetic categories, show that prototypes play a unique role in speech perception. Phonetic category prototypes function like "perceptual magnets" for other stimuli in the category. They attract nearby members of…