This is the first study of a community sample to examine the association between density of alcohol problems in the biological family and multiple childhood externalizing behaviors in the offspring. We found small but statistically significant associations between family density and two components of externalizing behavior: one composite variable reflecting difficulties with attention, impulse control, and overactivity, and another composite reflecting disturbance of conduct and aggression (i.e., behaviors generally reflecting problems with socialization). Theoretically suggested and practically significant moderating and mediating influences were found. The relation between family density and child externalizing behaviors was moderated by parenting practices. Family density was associated with child behavior only when parenting (e.g., monitoring of child’s whereabouts, consistency of discipline) was rated below median levels for the sample. Current demographic advantage (two parents, maternal education beyond high school) and current maternal mental health mediated the association between family density and child behavior, above and beyond the influences of other parent characteristics. Together these findings suggest that inherited vulnerability to alcoholism is visible in children’s behavior before the onset of alcohol consumption, that parental resources
