Siblings of disabled children: birth order and age-spacing effects.

Whereas older siblings of children with congenital disability have lived their earliest years in a "normal" family environment, younger siblings, especially those in a close age-spacing relationship, were born into families marked by the presence of a disabled child. In this paper, 327 siblings of disabled children are compared to 248 siblings from a random sample of families to examine whether the early family environment of siblings of disabled children, as indexed by relative birth order and age-spacing, has a unique influence on psychological functioning. The findings partially confirmed the expected relationships: Younger male siblings, specifically those in close age-spacing relationship to the disabled child, scored higher on psychological impairment than older male siblings. Among female siblings, a similar influence was not in evidence: Younger female siblings were psychologically better off than older female siblings and their age-spacing was not significantly related to psychological functioning. However, the results suggest that siblings' later response to early life experience may be sex-contingent, with males demonstrating interpersonal aggression and females experiencing depressive-anxious feelings.