“Development of Exclusivity in Perceptually Based Categories of Young Infants”, 1994-12 (; backlinks):
[cf. 1996] The exclusivity of perceptually defined categorical representations for natural animal categories in young infants was investigated.
Previously, as well as in Experiment 1, evidence was obtained for a categorical representation for cats in 3–4-month-old infants that excluded dogs but included perceptually similar female lions after several different familiarization procedures.
However, in Experiment 2 both dogs and female lions were found to be excluded when the initial familiarization with cats alone was followed by 6 pairings of familiar cats and novel lions intermingled with two added pairings of familiar cats.
The present results indicate that a categorical representation can attain a high level of exclusivity during early infancy as a consequence of experience with exemplars of the contrasting categories that accents the perceptual similarities among members of a category and the perceptual differences among exemplars from different categories.