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Behavior genetic methods are useful for examining mechanisms underlying the interaction between genetic and family environmental factors of internalizing problem behavior (INT). Previous twin studies, however, have shown little consistency in interaction patterns, depending on type and operationalization of measured environments. The aim of the current study was to explore different gene-by-environment interaction patterns among different family-level environmental risk factors and resources known to correlate with INT. Using an empirical-based approach, we combined various indicators of the family environment to derive four dimensions: positive parenting, negative parenting, lack of parental resources, and socioeconomic status. We then used a genetically informed design of twins raised in the same family to test whether interaction patterns followed a diathesis stress or vantage sensitivity model formulation. The sample consisted of 2,089 twin pairs and their families from two twin birth cohorts (ages 11 and 17) participating in Wave 1 of the German TwinLife study of social inequalities. In line with a vantage sensitivity pattern of interaction and with the bioecological model of development (Bronfenbrenner & Ceci, 1994), evidence for a general mechanism of gene–environment interaction with increasing nonshared environmental variance for more adverse and less propitious family conditions was found. In preadolescence, parenting behavior had a greater moderating influence on INT compared to general family conditions like socioeconomic status. Interventions for INT that directly involve parents, thus, may be more important in preadolescent populations whereas individual interventions for adolescents may be more successful if they are adapted to different levels of socioeconomic status. Public Significance Statement: The present study suggests that environmental influences outside the family may have a greater impact on internalizing problem behavior under less advantageous family conditions. In preadolescence, interventions for internalizing problem behavior should involve parents directly whereas in adolescence, interventions may be tailored individually that take into account adolescents' socioeconomic status. [ABSTRACT FROM AUTHOR]

This article uses a genetically informed design to evaluate whether (1) the well-documented association between marital support and depressive symptoms is accounted for by genetic and/or shared environmental selection, (2) gender differences are found after controlling for selection effects, and (3) parenthood moderates any nonshared environmental relation between depressive symptoms and marital support. We used a sample of 1,566 pairs of same-sexed, married twins from the Australian Twin Registry to evaluate our hypotheses that (1) the predicted effect of marital support on depressive symptoms is not fully an artifact of selection, (2) the etiological sources accounting for this effect differ between husbands and wives, and (3) parenthood status moderates the effect of marital support on depressive symptoms adjusting for selection effects. The results support the first hypotheses. However, after controlling for selection, the effect of marital support on depressive symptoms was not significantly different for husbands and wives. Parenthood moderated the effect of marital support, such that after controlling for selection, marital support is more strongly associated with depressive symptoms for full-time parents than nonfull-time parents. [ABSTRACT FROM AUTHOR]

Married adults have consistently been found to drink less than their single or divorced counterparts. This correlation may not be causal, however, as people nonrandomly "select" into marriage and into alcohol use. The current study uses a sample of 2,425 same-sex twin pairs (1,703 MZ; 722 DZ) to control for genetic and shared environmental selection, thereby eliminating a great many third variable, alternative explanations to the hypothesis that marriage causes less drinking. Married twins were compared with their single, divorced, and cohabiting cotwins on drinking frequency and quantity. Married cotwins consumed fewer alcoholic beverages than their single or divorced cotwins, and drank less frequently than their single cotwins. Alcohol use patterns did not differ among married and cohabiting twins. These findings provide strong evidence that intimate relationships cause a decline in alcohol consumption. (PsycINFO Database Record [ABSTRACT FROM AUTHOR]