The role of older siblings in younger siblings’ academic socialization becomes increasingly salient during adolescence. This longitudinal study examines the developmental mechanisms through which older siblings shape younger siblings’ academic outcomes and whether older siblings’ peer affiliations predict younger siblings’ educational aspirations and attainment. Data consisted of responses from 395 target adolescents (Mage = 12.22 years, 48.9% female; 51.6% African American, 38.5% European American) and their older siblings (Mage = 14.65 years, 50.1% female) across nine years. The findings showed that older siblings’ affiliation with academically disengaged peers at 7th grade predicted younger siblings’ decreased affiliation with academically engaged peers and increased affiliation with disengaged peers at 9th grade. In addition, younger siblings’ affiliation with academically engaged peers predicted greater educational aspirations at 11th grade, which in turn were related to higher postsecondary educational attainment. The identification of developmental processes through which older siblings were associated with younger siblings’ academic success may aid in creating supportive social environments in which adolescents can thrive.
