Older Sibling Prosocial Behavior Toward Younger Siblings During Adolescence: A Multi-Informant Multi-Method Investigation

Abstract

Adolescence is a time of increasing propensity to engage in prosocial behaviors toward family, with more recent work showing this proclivity toward siblings specifically. Sibling warmth and constructive problem-solving have been shown to promote adolescent well-being in several domains, but their contribution to adolescent prosocial decision-making towards siblings is unclear. Using multi-informant multi-methods data from 45 adolescent sibling pairs (older sibling: M_age = 14.5; younger sibling: M_age = 12.1) across time, this study examined whether dyadic sibling problem-solving (self-reported by both siblings) and observed warmth between siblings (coded from dyadic interactions) contributed to older "siblings" prosocial behavior toward young siblings (measured with an experimental task). We found a significant moderation, such that more constructive problem-solving predicted more prosocial decisions from older siblings to their younger siblings, but only when observed older sibling warmth toward younger siblings was high. These findings highlight the complex nature of relational processes in shaping older sibling prosociality toward younger siblings.