Previous studies indicate that the emotional quality of marital relationships is mirrored in parent-child relationships. We explored the degree to which these associations are explained by genetic and environmental factors. Participants were drawn from the Twin and Offspring Study in Sweden (TOSS), and included 544 female twin pairs (258 monozygotic [MZ], 286 dizygotic [DZ]), and 311 male twin pairs (128 MZ, 183 DZ). The spouses and one adolescent child of each twin also participated in this study. The twins completed self-report measures that assessed their marital quality and their warmth and negativity towards their children. Observational ratings of marital warmth and negativity, and of maternal warmth and negativity were obtained for a subset of female twin pairs (150 MZ, 176 DZ). Selfreported marital satisfaction was associated with self-reported parental warmth and negativity for mothers (rs = .25, -.36) and fathers (rs = .25, -.44). For the observational measures, marital warmth was associated with maternal warmth (r = .42), while marital negativity was associated with maternal negativity (r = .34). On average genetic factors explained nearly half of the covariance between selfreported marital satisfaction and parenting for mothers (48%) and fathers (47%). Genetic factors explained 21% of the covariance between observed marital and maternal warmth, but did not contribute to associations between marital and maternal negativity. These findings indicate that parents' genetically influenced characteristics help shape the emotional climate of the family.Over 3 decades of research have recognized that relationships within families affect each other. Of particular interest have been associations between parents' marital relationship and parent-child relationships. Previous studies report consistent associations between the parents' perceptions of the marital relationship, the presence of marital conflict, and parenting behaviors. In a meta-analysis of 68 studies, Erel and Burman (1995) found that on average, associations between indices of marital quality and parenting were moderate in magnitude. In a more recent meta-analysis, Krishnakumar and Buehler (2000) focused exclusively upon associations between marital conflict and indices of negative parenting (harsh discipline, lax control) and positive parenting styles (supportiveness and control). Similar to the earlier meta-analysis, high levels of marital conflict were correlated with greater use of harsh discipline and lower parental support.Although these associations are well established, the underlying mechanisms are not entirely clear. Current theories emphasize environmental mechanisms to explain consistencies in the expression of positive and negative affect across family relationships. For example, one predominant theory proposes that highly conflictual or poor quality marriages place emotional stress on parents, leading to deterioration in parenting quality (e.g., Easterbrooks & Emde, 1988). A second explanation is that emotions and behaviors from one r...