The role of siblings and psychological needs in predicting life satisfaction during emerging adulthood

Life satisfaction during emerging adulthood is important because it promotes positive psychological functioning and prevents risky behaviors that lead to poor health. Self-determination theory emphasizes the agentic nature of individuals to maintain well-being through the psychological needs of autonomy, competence, and relatedness, and the social contexts which influence these processes. Because siblings serve as an emotional resource throughout the life span, sibling support may predict well-being through these psychological needs. With this framework as a guide, 337 individuals from the Family Transitions Project reported sibling support at 17 years old, sense of autonomy, competence, and relatedness at 19 years old, and life satisfaction at 20 years old. Sibling support in adolescence was significantly associated with autonomy, competence, relatedness, and life satisfaction in emerging adulthood. Sense of competence mediated the association between sibling support and later life satisfaction. Results highlight the unique influence of siblings in contributing toward life satisfaction.