Number of Siblings and Mental Health Among Adults: A Life Course Resource Dilution Model

Scholars observe an inverse association between sibship size and mental health among adolescents, but how do siblings matter when children become adults and tend to live away from parents and each other? We modify the Resource Dilution Model, suggesting that, as individuals age, the influence of parents declines and sibling are more likely to become resources and less likely to remain competitors. We then test the association between number of siblings and indicators of mental health among American adults in the General Social Surveys ( n ∼ 62,000) and European adults in the Survey of Health, Aging, and Retirement in Europe (SHARE) ( n ∼20,000). In contrast to the patterns among adolescents, we find that associations between sibship size and mental health indicators are typically neutral or positive. We conclude that, when people enter adulthood and later life stages, siblings tend to play a more positive role in their lives.