Personality, Marital Satisfaction, and Probability of Marital Infidelity

Personality and marital satisfaction may help to account for the likelihood of marital infidelity. We hypothesized that people with particularly disagreeable spouses (i.e., those low on Agreeableness) and particularly unreliable spouses (i.e., those low on Conscientiousness) will be less satisfied with their marriage, leading them to estimate a higher probability of becoming extramaritally involved in the next year. Two hundred fourteen newlyweds comprising 107 couples completed measures assessing their personality, their marital satisfaction, and their likelihood of infidelity. The results provide some evidence that personality and marital satisfaction may help to account for which marriages are likely to include infidelities and which are likely to remain faithfully intact. Infidelity is a subject that confronts couple therapists regularly in their clinical practices. It can be a confusing and heart-wrenching experience for all involved, including the therapist who may have his or her own personal fears and values related to infidelity (Glass & Wright, 1997). Moreover, infidelity is a major cause of Shackelford et al. / Individual Differences Research, 2008, Vol. 6, No. 1, pp. 13-25 14 divorce and spousal battering (see Buss, 2004; Daly & Wilson, 1988). Little is known, however, about which individuals are susceptible to infidelity. Personality psychologists seek, in part, to describe parsimoniously variation in human cognition, affect, and behavior. One approach to this descriptive effort is known as the “Five Factor Model” (FFM) of personality (see John, 1990, for a review of the FFM). The FFM is rooted in a lexical approach to understanding variation in human personality. A lexical approach holds that the most important variation in human cognition, affect, and behavior will have been encoded into the language. The pioneers of the FFM began by extracting all trait descriptive adjectives from the dictionary. These investigators then asked people to rate themselves and various target others along each of the trait terms. These ratings are then orthogonally factor-analyzed. Researchers analyzing different languages and working in different cultures find that these trait ratings tend to reduce to variation along five major factors (see John, 1990). In order of the percentage of total rating variation accounted for per factor, the first factor of the FFM (Surgency) captures variation along the Extraverted— Introverted dimension. The second factor (Agreeableness) captures variation along the Agreeable—Disagreeable dimension. The third factor (Conscientiousness) describes variation along the Reliable—Unreliable dimension. The fourth factor (Emotional Stability) describes variation along the Emotionally Stable—Neurotic dimension of personality. Finally, the fifth factor (variously labeled Openness to Experience, Intellect, or Culture) describes variation along social and intellectual acuity (John, 1990, and references therein). The FFM has been used to describe marital interactions as the interface between two personalities (Buss, 1989, 1991). One area of interest is whether the personalities of the married couple might predict various marital outcomes. What type of person, for example, is likely to divorce their spouse? Might they be significantly lower on Agreeableness than those who do not divorce? Or perhaps those who divorce are higher on Openness to Experience than are those who do not eventually divorce. Another notable marital outcome is infidelity. Can an individual’s standing along one or more of the five factors predict whether they might become romantically involved with someone outside of the marriage? And can a person’s standing along one or more of the major personality dimensions predict whether he or she might become the victim of marital infidelity? Atkins, Baucom, and Jacobson (2001) report that, “infidelity is a common phenomenon in marriages but is poorly understood" (p. 735; and see Atkins, Dimidjian, & Jacobson, 2001; Blow & Hartnett, 2005; Glass & Wright, 1988, 1997; Thompson, 1983). Laumann, Gaugnon, Michael, and Michaels (1994) found that Shackelford et al. / Individual Differences Research, 2008, Vol. 6, No. 1, pp. 13-25 15 77% of their participants believed that extramarital sex was always wrong. Such disapproval may stem from a general belief that infidelity is immoral (Blumstein & Schwartz, 1983; Prins, Buunk, & VanYperen, 1993). Infidelity and the desire for more than one partner are clearly important factors of sexual risk taking and strongly underpinned by individual differences. A meta-analysis of 45 studies examining personality factors underlying sexual risk behavior found high agreeableness and high conscientiousness reliably correlated with lower sexual risk taking (Hoyle, Fejfar, & Miller, 2000). Low agreeableness correlated negatively with greater sexual risk taking, including multiple partners; for low conscientiousness, the strongest correlation was with unprotected sex. This study did not indicate that low conscientiousness is related to sexual promiscuity, although sensation seeking and impulsivity (sharing constructs with low conscientiousness) are strongly predictive of sexual risk taking. Miller, Lynam, Zimmerman, Logan, Leukefeld, and Clayton (2004) found that low straightforwardness [one facet of the agreeableness construct within Costa and McCrae’s ‘‘Big-Five’’ model (e.g., Costa & McCrae, 1992a, 1992b; McCrae & Costa, 1996), characterized by manipulative, deceitful behavior] also was a strong predictor of sexual promiscuity. Relationship infidelity is reliably associated with low Agreeableness and low Conscientiousness. Schmitt and Buss (2000), for example, found that those with high levels of Agreeableness and Conscientiousness were higher in relationship exclusivity—that is, are less likely to be unfaithful. And across 10 world regions and 52 nations of the International Sexuality Description Project, low Agreeableness and low Conscientiousness were associated with relationship infidelity (Schmitt, 2004). Some studies support the idea that individuals engage in infidelity because there is something wrong in their primary relationship [i.e., as marital happiness or satisfaction decreases, the occurrence increases (Atkins, Baucom, & Jacobson, 2001; Glass & Wright, 1985)]. At the very least, suggest Prins et al. (1993), dissatisfaction in the primary relationship increases the desire for involvement in extradyadic relationships. Glass and Wright (1985) found the negative correlation between marital satisfaction and infidelity to be true for all types of extradyadic involvement (sexual, emotional, and combined sexual and emotional involvement), although they discovered that primary relationship dissatisfaction is particularly related to extradyadic emotional infidelity. Further, men and women who are involved in both sexual and emotional infidelities are even more dissatisfied with their marriages than are those engaged in either sexual-only or emotional-only infidelities (Glass & Wright, 1985). Although research has documented that Agreeableness and Conscientiousness are linked to the likelihood of marital infidelity, it is not known how these Shackelford et al. / Individual Differences Research, 2008, Vol. 6, No. 1, pp. 13-25 16 personality characteristics manifest themselves to become associated with marital infidelity. Here we present a causal model generated with reference to the FFM of personality to predict self-reported likelihood of becoming extramaritally involved. Specifically, we hypothesize that people with especially disagreeable partners (i.e., those low on Agreeableness) and particularly unreliable partners (i.e., low on Conscientiousness) will tend to be less satisfied with their marriage. This lower marital satisfaction will translate into higher estimates of the probability that the respondent will become extramaritally involved. In addition, attitudes toward infidelity (e.g., belief that infidelity is immoral) are important in that some research suggests that individuals with more permissive attitudes toward infidelity in relationships are more likely to engage in infidelity (Treas & Giesen, 2000), thus we hypothesize that the respondents’ own level of Conscientiousness will have a direct effect on their estimate of the likelihood that they will be unfaithful to their partner. That is, more conscientious respondents will report a lower probability that they will become extramaritally involved. In sum, the present research addresses three key questions: (a) Do people with especially disagreeable partners (i.e., those low on Agreeableness) and particularly unreliable partners (i.e., those low on Conscientiousness) tend to be less satisfied with their marriage? (b) Does lower marital satisfaction translate into higher estimates of the probability that the respondent will become extramaritally involved? (c) Does the respondents’ own conscientiousness have a direct effect on their estimate of the likelihood that they will be unfaithful?