Exploring Linkages Between Mother–Child and Sibling Relationship Quality and Prosocial Behavior Between School-Aged and Adolescent Siblings

The present study investigated the degree to which the quality of sibling relationships interacted with the quality of mother-child relationships to concurrently predict prosocial behavior between school-aged siblings while taking age spacing into account. Forty-five families with two school-aged siblings were recruited from the community. Prosocial behavior was coded from unstructured laboratory observation of sibling interaction. Both children reported on the quality of their sibling relationships; the quality of mother-child relationships was assessed by coding laboratory observation of mother-child interaction, conducted separately with each sibling. A compensatory pattern was found; higher warmth between widely spaced siblings was associated with greater sibling prosocial behavior when maternal positivity was low, and also when maternal negativity was high. These compensatory patterns did not occur for siblings closer in age. Findings suggested that sibling dynamics and relational roles play an important function in children's prosocial development. Results were discussed within family systems frameworks.