when the children are aged 3–5; beginning at age 11, participants are assessed every year. Families are excluded if the target child displays evidence of fetal alcohol effects or the mother reports drinking during pregnancy. Full details on the MLS can be found elsewhere (Zucker et al., 1996; 2000). In order to avoid problems with population stratification, only data from non-Hispanic White participants were included. This racial/ethnic class constitutes 82.5% of the MLS sample from which this study sample was drawn. See Table 1 for demographic and behavioral variables.
