The differentiation hypothesis: distinguishing between perceiving and memorizing

The differentiation hypothesis states that perceiving and memorizing are functionally undifferentiated for young children (preschoolers). With age, additional strategies are implemented under intentional recall conditions, thus providing greater recall than under incidental conditions. Appel and colleagues presented initial evidence in 1972 that appeared to support the predicted Age X Recall Instruction (incidental, intentional) interaction of the differentiation hypothesis. Subsequent research in children's memory, however, has failed to replicate the critical features of the Appel et al. data. A closer look at Appel et al.'s procedures revealed a methodological flaw present in both their Experiments 1 and 2--the variable of instructional condition was manipulated within subjects. In addition, an inspection of their reported Age X Instruction interaction revealed a larger quadratic than linear component. The difference between incidental and intentional recall first increased and then decreased with age. Correcting for these errors of method and analysis, the present experiment found no support for the differentiation hypothesis. Recall did increase with age, but the increase was not differential with respect to incidental or intentional recall instructions.