Examining Personality and Relationship Satisfaction Using Biometric and Longitudinal Approaches

Romantic relationship satisfaction (also variously referred to as relationship adjustment or relationship quality) has been well studied as a construct in the social and clinical psychology literatures. One of the most well-known theories of relationship satisfaction and stability suggest that it is the interplay between three groups of variables—enduring vulnerabilities, stressful life events, and adaptive processes (i.e., Vulnerability-Stress-Adaptation (VAS) model)—that impact how satisfying and ultimately how stable a relationship is (Karney & Bradbury, 1995). There is extant behavior genetic research examining the genetic and environmental influences on relationship satisfaction. While previous literature has looked at the heritability of marital satisfaction in older adults (e.g., Spotts et al., 2004), our knowledge about the genetic and environmental influences on relationship satisfaction in older adult samples remains fairly limited. Spotts and colleagues (2004) demonstrated that the nonshared environment had the largest influence on variation in marital quality reports. As an extension of this work, the present research intends to estimate heritability in an older adult twin sample from the MTR. Findings on the genetic and environmental influences on marital satisfaction will guide the subsequent areas of interest in personality. Once we establish the genetic and environmental influences on relationship satisfaction in the MTR sample of older adult twins, we will investigate the genetic and environmental overlap between marital satisfaction and personality. Personality has garnered much attention because of its impactful role in shaping people’s social relationships; and more specifically, close, romantic relationships (Robins et al., 2000; South et al., 2016). According to the VSA, personality is an enduring vulnerability that can affect how one interacts with their partner in a relationship during times of stress which can contribute to conflict-laden interactions. Lower levels of relationship satisfaction may indicate the presence of maladaptive personality traits in one or both partners which may in turn lead to interpersonal dysfunction (Yu et al., 2025). Personality traits are relevant in shaping an individuals’ marital experience. Spotts and colleagues (2005), for example, found wives’ personality characteristics significantly accounted for genetic and environmental variance in their ratings of marital satisfaction, their partner’s satisfaction, and agreement between the partners’ perception of their marital quality. Their work helps emphasize the important role personality plays within a relationship; however, the use of specific trait-like behavioral dispositions (e.g., optimism and aggression) limits the scope of how much personality (e.g., the Big Five) can be expressed and subsequently influence a relationship’s quality. Prior literature (South & Krueger, 2008; Spotts et al., 2004) has found moderate genetic influence on marital satisfaction, which leads to a further interest in considering how marital satisfaction acts as a moderator. Work by South and authors (2016) demonstrated how romantic relationship satisfaction can moderate genetic influences on an individual’s personality; but to our knowledge, there have not been studies that have tested the heritability of personality changing as a function of marital satisfaction in older adults. We will examine if marital satisfaction could intensify or buffer genetic influences on personality expression in later-life relationships. For example, a person experiencing high satisfaction in their relationship may suppress genetic vulnerabilities that relate to maladaptive personality traits, suggesting, that unique, unshared experiences might better explain this level of satisfaction. We will also run exploratory analyses examining the heritability of marital satisfaction changing as a function of personality. We have no anticipated priori hypotheses. Another direction worth exploring is the longitudinal effects of personality on romantic relationships outcomes. Robins et al. (2002) demonstrated the importance of personality as a predictor for subsequent relationship satisfaction, and by using the MTR sample and MTFS sample, we have the unique ability to understand how personality subsequently affects relationship satisfaction in two developmental periods of life.