An initial look at sibling reports on children's behavior: comparisons with children's self-reports and relations with siblings' self-reports and sibling relationships.

The authors examined siblings' reports of children's depression, anxiety, and aggression, and their reports of the sibling relationship, and compared them with children's self-reports. In two samples, including 169 sibling pairs (age M = 9.98 years, SD = 1.51), no significant differences emerged in the levels of depression and anxiety found in siblings' reports of children's behavior and children's self-reports, although siblings reported children to have significantly higher levels of aggression than the children self-reported. Age, the difference in ages between siblings, sex, and sibling sex were not related to siblings' reports of children's behavior. The relations between children's and siblings' reports of children's behavior were significant, yet moderate (average r = .22). Both siblings' self-reports of internalizing behavior and their perceptions of aspects of the sibling relationship (affection, rivalry, hostility, and satisfaction with the sibling relationship) explained significant, and unique, variance in siblings' reports of children's internalizing behavior. The findings for aggressive behavior were similar, although siblings' perceptions of affection in the sibling relationship were not significantly related to their reports of children's aggression. The potential uses and benefits of sibling reports of children's behavior, and sibling and family relationships, are discussed.