Birth order effects and their implications for child care research and programs

Using previously collected data on the effects of different child care environments on children 4 to 5 1/2 years old, results supporting Zajonc and Markus's confluence model of the interactive effects of family size, birth order, and age between siblings as predictors of intelligence were found for only children. Consistent with an ecological perspective, family patterns were seen as important in evaluating the impact of different child care modalities and in finding optimal child care settings for children from different family structures.