Data from the National Child Development study (NCDS) were used to examine predictors of attainment among adoptees, nonadopted children from similar birth circumstances, and other members of this national birth cohort. Adoptees performed more positively than nonadopted children from similar birth circumstances on childhood tests of reading, mathematics, and general ability, and retained this advantage in school-leaving and later adult qualifications. In addition to family SES and material circumstances, measures of the educational environment of the home and of parental interest in education emerged as central predictors of these variations. Further analyses suggested possible differences in the mode of operation of these variables between boys and girls, and at different stages of young people's educational careers.