Effects of modeling action sequences on the play of twelve-, fifteen, and nineteen-month-old children.

3 studies examined the relation between the spontaneous occurrence in play of simple 2-part action sequences and the frequency of these sequences and their components following modeling at 12, 15, and 19 months of age. Play following modeling was typically more advanced than play preceding modeling. Moreover, imitation was tied to developmental level. Children at 19 months of age were generally able to imitate complete sequences, though only a few 19-month-olds performed such actions spontaneously. Children at 15 months of age typically did not imitate complete sequences except under simplified experimental conditions, and, even then, their ability to perform sequences was attenuated relative to the 19-month-olds. However, 15-month-olds did imitate many single components of the 2-part combinations and, to a lesser extent, exhibited these components spontaneously. A smaller number of 12-month-olds imitated components, which were rarely displayed spontaneously at this age. The results suggested that a general combinatorial capacity in play emerges between 15 and 19 months of age.