Rule selection versus rule execution in preschoolers: An error-detection approach

In 2 experiments, an error-detection approach was used to determine whether 3-year-olds' perseverative errors on the postswitch phase of the Dimension al Change Card Sort (DCCS) are due to lack of response control or represent ational inflexibility. In Experiment I, 3-, 4-, and 5-year-olds watched a p uppet sort perseveratively on the postswitch phase and evaluated its respon ses. Most 4- and 5-year-olds detected the puppet's perseverative errors, wh ereas most 3-year-olds failed to do so despite detecting errors on a simple r card sea. Experiment 2 revealed that 3-year-olds who failed to correctly evaluate the puppet's behavior tended to fail their own DCCS. Results imply that perseveration on the DCCS cannot be attributed to difficulty inhibiti ng prepotent motor responses. Instead, changes in rule use between 3 and 5 years of age are interpreted in terms of the development of representationa l flexibility.