Siblings as models in early infant learning.

4 groups of infants, 2 at 6 months and 2 at 12 months, were tested on the Stage IV-V and V-VI object concept tasks. All groups were then retested on the same tasks 1 week later. Retesting of the experimental groups was preceded by an all-correct demonstration of the 2 search tasks by the infant's preschool sibling; control groups were not exposed to any model prior to reassessment. No effect of exposure to the sibling model was initially found in either age group. If, however, infants' initial stage of development was taken into account, cognitive performance on the lower-level task did show a significant improvement after modeling. Overall, the results suggest that sibling modeling could possibly be an effective method of facilitating cognitive development in infancy, but that the success or failure of any modeling attempt may be stage- rather than age-dependent.