Environmental differences within the family and adjustment differences within pairs of adolescent siblings.

To what extent do siblings in the same family experience different parental treatment, sibling interaction, and peer relationships? Are such within-family experiential differences related to differences in the siblings' emotional adjustment? The present study explored these questions concerning within-family environment using data from 348 families that each included 2 siblings 11-17 years of age. The results indicate that siblings in the same family experience different environments, as reported by parents and to a larger extent by the siblings themselves. The results also demonstrate that within-family environmental differences are related to differences in development between siblings. Both the parent and sibling reports of the environment converge on the finding that the sibling who is more psychologically well adjusted (as reported by parents, siblings, and teachers) also experiences more maternal closeness, more sibling friendliness, more peer friendliness, more say in family decision making, and more parental chore expectations as compared to the other sibling.