Sibling Conflict and Closeness: The Effects of Sex, Number of Siblings, Relatedness, Parental Resemblance and Investment

Siblings may be our staunchest supporters as well as our most significant rivals. What factors shape these sibling relationships into ones of conflict versus closeness? Are conflict and closeness shaped by the same factors, occupying opposite ends of the same spectrum? Or are conflict and closeness independent of each other, being shaped by different factors? The current study examined conflict and closeness between siblings as a function of respondent sex; sex of sibling; genetic relatedness; age difference; time spent together; and perceived parental resemblance, investment, and favoritism. Results indicate the factors that shape conflict differ from those that shape closeness, suggesting they are not simply opposite ends of the same spectrum. While genetic relatedness, perceived parental favoritism, and sex of sibling relative to the respondent explained most of the variance in sibling conflict, most of the variance in sibling closeness was explained by time spent with the sibling and perceived sibling resemblance-not genetic relatedness. Furthermore, the factors examined in the study explained much more variance in closeness than in conflict. Future research utilizing within-family designs as well as cross-cultural data will be useful in adding to our understanding of how sibling conflict and closeness are shaped.