Reviews data from the "High School and Beyond" study to examine sibling intellectual symmetry and the degree to which family background affects the siblings' intellectual ability. Finds considerable symmetry in intellectual skills. Discovers little impact on symmetry from gender or birth order. (CFR)

Suggests that intellectual ability is a stronger determinant of academic success than family income, parental education, or socioeconomic status. Maintains that familial influence plays an important role in academic achievement but questions the specifics of that relationship. Includes statistical information on grade variation, siblings, and…