Four experiments examined children's ability to use their knowledge to guide their behavior in a dimensional change (color-shape) card sort. In Experiment 1, 3- and 4-year-olds were told to sort cards first by one dimension (e.g., color: "Yellow ones go here; green ones go there") and then by the other. The majority of 3-year-olds continued to use the preswitch rules on the postswitch phase, despite expressing knowledge of the postswitch rules by pointing to the appropriate location when asked about each rule. Experiment 2 found that this dissociation between knowledge and its use occurs even after a single preswitch trial. Experiments 3 and 4 demonstrated that the dissociation also occurs when verbal rather than manual responses are required. Together, the findings indicate that knowing rules is sometimes insufficient to permit their use. According to the cognitive complexity and control theory, the growth of reflection between 3 and 5 years of age underlies increases in control over thought and action by allowing children to integrate incompatible pairs of rules into a single rule system.
Bibliographical noteFunding Information:
This research was supported by a grant from the Natural Science and Engineering Research Council of Canada to the first author. The authors would like to thank S. Reznick, S. Mar-covitch, and two anonymous reviewers for their helpful su&estions; and M, Scharer, 3. Schus-ter, and A. Winters for their help with data collection. T. Rapus is now at M&ii University.