In the report of the Task Force established by the American Psychological Association to examine issues associated with the nature of intelligence and the meaning of intelligence test scores, Neisser et al. (1996) concluded that “the environmental contributions to those [individual] differences [in intelligence] are almost equally mysterious. We know that biological and social aspects of the environment are important for intelligence, but we are a long way from understanding how they exert their effects” (p. 96). This chapter develops a moderation-mediation model to examine relationships between family capital and children’s cognitive performance. The model is generated from Bourdieu’s theory of the social trajectory of individuals and from the bioecological model of human development proposed by Bronfenbrenner and Ceci (1994) and Ceci, Rosenblum, de Bruyn, and Lee (1997).