Preschool children's understanding of causal connections

Preschool-aged children's understanding of causal mechanism was assessed by showing them a simple event sequence in which two objects moved in tandem. The central question was whether children would infer the presence of a mechanism linking the two objects whose movement covaried. This was tested by assessing five responses: actions when asked to move one object, explanations for how the object moved, predictions as to whether both objects would still move without a connection, inferences about the nature and location of the connection, and surprise when the objects moved without any apparent connection. The results from 3-, 4- and 5-year-olds indicated that an understanding of mechanism is firmly established by 5 years but fragile at 3 years and only revealed by some response modes. The implications of the results concerning how to characterize and test for early competence are discussed.