Sibling relationships have been described as love-hate relationships by virtue of their emotional intensity, but we know little about how sibling positivity and negativity operate together to affect youth adjustment. Accordingly, this study charted the course of sibling positivity and negativity from age 10 to 18 in African American sibling dyads and tested whether changes in relationship qualities were linked to changes in adolescents' internalizing and externalizing behaviors. Participants were consecutively-born siblings [at Time 1, older siblings averaged 14.03 (SD = 1.80) years of age, 48 % female; younger siblings averaged 10.39 (SD = 1.07) years of age, 52 % female] and two parents from 189 African American families. Data were collected via annual home interviews for 3 years. A series of multi-level models revealed that sibling positivity and sibling negativity declined across adolescence, with no significant differences by sibling dyad gender constellation. Controlling for age-related changes as well as time-varying parent-adolescent relationship qualities, changes in sibling negativity, but not positivity, were positively related to changes in adolescents' depressive symptoms and risky behaviors. Like parent-adolescent relationships, sibling relationships displayed some distancing across adolescence. Nevertheless, sibling negativity remained a uniquely important relational experience for African American adolescents' adjustment.
Keywords: Adolescent adjustment; African American families; Externalizing; Internalizing; Sibling relationships.