order; these effects are often cumulative across multiple risk and protective factors (Rutter, 1979; Sameroff, Guttman, and Peck, 2003; Sandler, Ayers, and Romer, 2001).
In moderational models, a protective factor may reduce the relation between a risk factor and disorder, or a vulnerability factor may exacerbate the relations between a risk factor and disorder. In looking at the relations between stress and psychopathology, for example, such variables as intelligence or academic achievement and positive family environment moderated the adverse effects of stress (Grant, Compas, et al., 2006). Significant interactions have also been found between cumulative indices of risk and protective factors related to community, school, family, and individual variables (e.g., opportunities for school involvement, family attachment, and social problem-solving skills) in predicting substance use, delinquency, and school problems (Pollard, Hawkins, and Arthur, 1999). The aggregated protection measure reduced the odds for a problem outcome when the score on the aggregated risk measure was high, but not when the score was low. However, Grant, Compas, and colleagues (2006) point out that it is difficult to draw general conclusions concerning moderators of stressors because available studies test effects across different stressful situations and different outcomes and use different measures to operationalize the constructs. A clear conceptual framework is needed to integrate findings across putative protective factors. For example, the moderating role of cognitive variables in the effects of stress on depression is established because of well-established theoretical models of depression.
In mediational models, a chain of events is hypothesized in which the effects of risk or protective factors operate through their effects on another risk or protective factor, which in turn affects the development of mental, emotional, and behavioral problems. Particularly when there is a temporal relation among the factors, mediational models provide a powerful approach to looking at the pathways for the development of disorder over time (Cole and Maxwell, 2003; MacKinnon, 2008). Parenting has been found to be a mediator of the effects of multiple risk factors, including poverty, parental divorce, parental bereavement, and parental mental health problems (Sampson and Laub, 1993; Simons, Johnson, et al., 1996; Kwok, Haine, et al., 2005; Grant, Compas, et al., 2003; Wolchik, Wilcox, et al., 2000; Wyman, Sandler, et al., 2000), and multiple interventions have been designed to strengthen parenting (see Chapter 6).
Both moderational and mediational models also show that risk and protective factors in one context (e.g., the family) may influence or be influenced by factors in other contexts. A meta-analysis found that the effects of poverty on children’s internalizing and externalizing problems was partially mediated through its effects to impair effective parenting (Grant, Compas, et al., 2003), whereas other studies found that the effects of poverty are