Adjustment problems of sibling and nonsibling pairs referred to a school mental health program.

Studied 41 pairs of sibling and 41 pairs of nonsibling primary-grade children. Using 2 teacher behavior-rating forms and a frequency rating scale of 1-5, results show that mean differences between siblings were directionally smaller than those between nonsiblings on all 8 measures, significantly on 5. For like-sex pairs, all 8 mean sibling differences were smaller than the comparable nonsibling differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)