operating. Maternal distress and decreased “social capital” (Elgar et al., 2004) may be associated with child behavior for reasons that are environmental as well as genetic, and unidirectional or bidirectional (Rutter, 1990). For example, there is a well-established association between maternal depression and child emotional and behavioral adjustment that is believed to reflect genetic and other biological and social factors (Elgar et al., 2004). Finally, the finding that mediation of density effects was explained by mother and not by father mental health is probably a function of the higher density of alcoholism within the single mother-headed families. Had absentee (and potentially alcoholic) fathers been interviewed in these families, we might have found more mediation through current father functioning. Mediation through mother mental health may partly reflect the difficulty of raising, perhaps single-handedly, children with challenging behavioral profiles. Another explanation for the absence of mediation through father mental health might be participation by non-biological (and potentially healthier) step-fathers. However, only 10% of participating fathers/partners were not biologically related to the child in the study.
