The results of the current study mesh well with previous genetically informative research on marital satisfaction. We replicated previous work that found moderate estimates of heritability for marital quality (Spotts et al., 2004b; Spotts et al., 2006). In many ways, it is not surprising that there are genetic effects on an “environmental” variable. There are now numerous studies that document genetic influences on measures of family environment (see Kendler & Baker, 2007, for a recent review). One hypothesis that has been substantiated in several studies is that genetic effects on environmental variables are due to personality traits (Chipuer, Plomin, Pedersen, McClearn, & Nesselroade, 1993; Krueger, Markon, & Bouchard, 2003; South, Krueger, Johnson, & Iacono, 2007). In the only study to examine genetic and environmental overlap between marital quality and personality, there were significant genetic correlations between marital satisfaction and a personality composite of optimism and aggression (Spotts et al., 2005a). Here we extend this work to show that genetic effects on marital quality are shared in common with the internalizing spectrum, which includes a neurotic personality style. Hopefully this will
