Examines preschoolers' understanding of non-observable causal mechanism in causes of illness. Three studies were conducted using subjects from university child care centers. Subjects average five years of age. Results indicated that preschoolers recognize that appearances may be deceiving when it comes to judging causes of illness. Discusses…

A study with three- and five-year olds contrasted two important proposals regarding children's assumptions about word meanings: the taxonomic assumption proposal and the shape bias proposal. Results suggest that perceptual similarity, particularly shape similarity, is very important in early word meaning but that children gradually shift their…

Tested children with apparatus that dropped balls through clear or opaque interwoven tubes. Found that older children could solve configurations with greater number of tubes than younger children. Success with clear tubes did not transfer to opaque tubes. Significantly, errors were consistently directed to location directly below ball's last seen…