and Grant Edmonds Compensatory Conscientiousness and Health in Older Couples

The present study tested the effect of conscientiousness and neuroticism on health and physical limitations in a representative sample of older couples (N 5 2,203) drawn from the Health and Retirement Study. As in past research, conscientiousness predicted better health and physical functioning, whereas neuroticism predicted worse health and physical functioning. Unique to this study was the finding that conscientiousness demonstrated a compensatory effect, such that husbands’ conscientiousness predicted wives’ health outcomes above and beyond wives’ own personality. The same pattern held true for wives’ conscientiousness as a predictor of husbands’ health outcomes. Furthermore, conscientiousness and neuroticism acted synergistically, such that people who scored high for both traits were healthier than others. Finally, we found that the combination of high conscientiousness and high neuroticism was also compensatory, such that the wives of men with this combination of personality traits reported better health than other women. Conscientiousness refers to individual differences in the propensity to follow socially prescribed norms for impulse control, to be task and goal directed, to be planful, to delay gratification, and to follow norms and rules (John & Srivastava, 1999). A study by Friedman et al. (1993) showed that conscientiousness predicts longevity. Specifically, participants in this study tended to live longer if, as 8-year-olds, they had been rated as more conscientious by parents and teachers. These effects held after controlling for gender and parental divorce, two known influences on longevity. The positive effect of conscientiousness on longevity has now been replicated across several studies and more heterogeneous samples (Kern & Friedman, 2008; Roberts, Kuncel, Shiner, Caspi, & Goldberg, 2007). Consistent with the finding that conscientiousness predicts longevity, research has shown that conscientiousness predicts most of the major preventive and risky behaviors associated with both physical health and mortality (Bogg & Roberts, 2004). Conscientiousness also predicts physical health itself. For example, low levels of conscientiousness are associated with diabetes, high blood pressure, skin problems, strokes, ulcers, and tuberculosis (Goodwin & Friedman, 2006). Similarly, of the Big Five personality traits, conscientiousness was shown to be the best predictor of illness burden (i.e., physician-quantified morbidity) even when controlling for education, substance abuse, hypertension, and cholesterol (Chapman, Lyness, & Duberstein, 2007). In addition, childhood ratings of conscientiousness predict midlife health ratings even when controlling for social environmental factors such as education and healthrelated behaviors (e.g., exercise, diet, and smoking; Hampson, Goldberg, Vogt, & Dubanoski, 2007). Conscientiousness has even been shown to predict slowed disease progression in HIV patients (O’Cleirigh, Ironson, Weiss, & Costa, 2007). The majority of research linking conscientiousness to health outcomes has been predicated on the reasonable assumption that it is the person’s own personality that will affect his or her health outcomes. This assumption overlooks the possibility that the personalities of people in an individual’s close social network may also affect his or her health outcomes. More specifically, spouses or caretakers who are more conscientious may be more reliable caregivers and therefore enhance the health of their partners. We refer to this as the compensatory conscientiousness effect. The idea of compensatory conscientiousness was inspired by couples research showing that spouses’ personality contributed to their partners’ important life outcomes. For example, a prospective longitudinal study found that women who were more individualistic were subsequently more successful in their work, and that women who were married to more individualistic husbands were evenmore successful (Helson&Roberts, 1992). The contribution of husbands’ personality to wives’ work outcomes was independent of the women’s own personality traits. Similarly, research on the effect of couples’ personality traits on Address correspondence to Brent W. Roberts, Department of Psychology, University of Illinois, 603 East Daniel St., Champaign, IL 61820, e-mail: broberts@cyrus.psych.uiuc.edu. PSYCHOLOGICAL SCIENCE Volume 20—Number 5 553 Copyright r 2009 Association for Psychological Science at WASHINGTON UNIV SCHL OF MED on August 26, 2014 pss.sagepub. com Downloaded from marital outcomes has shown that one’s partner’s personality has an effect on one’s own outcomes, such as marital satisfaction (Robins, Caspi, & Moffitt, 2000). In this work, self-reported negative emotionality, a component of neuroticism, predicted lower self-reported relationship satisfaction. Moreover, partners’ negative emotionality predicted spouses’ reports of relationship satisfaction above and beyond the effect of spouses’ own levels of negative emotionality. Two health-related studies have shown similar patterns. In the first study (van Aken, Junger, Verhoeven, van Aken, & Dekovic, 2007), lower maternal conscientiousness predicted greater numbers of minor injuries in toddlers in an analysis controlling for background factors and ratings of the toddlers’ temperament. This study is not an ideal demonstration of compensatory conscientiousness, however, as the temperament ratings came from the parents, who also completed the self-report personality measures. Amore compelling example comes from a study of the effects of child and parent personality on glycemic control (i.e., control of blood sugar levels) in a sample of diabetic children ages 6 to 16 (Vollrath, Landolt, Gnehm, Laimbacher, & Sennhauser, 2007). The children were followed for 2 years, and the researchers found that those who rated themselves as more conscientious had better glycemic control, asmeasured by blood analysis. In addition, in an analysis controlling for the children’s personality, children of mothers who were more conscientious had better glycemic control, a finding consistent with the idea of compensatory conscientiousness. Clearly, the couples and health research supports the possibility that it is good for one’s health to have a conscientious person in one’s social-support network, but to our knowledge the idea of compensatory conscientiousness has never been tested directly in the health domain. To test the interplay of partners’ personality in influencing health outcomes, we examined the association of personality and health ratings among more than 2,000 couples taking part in the Health and Retirement Study (HRS), a nationally representative study of the population over age 50. The structure of the data, being partly based on couples, allowed us to examine multiple pathways by which conscientiousness might influence health. The first possibility is that the individual’s own personality is predictive of his or her outcomes. The second possibility, which captures the idea of compensatory conscientiousness, is that a partner’s personality adds to the prediction of a person’s outcomes. The third possibility is that a husband’s and wife’s personality traits act synergistically (i.e., in a multiplicative way) on health outcomes, such that the personality of an individual’s partner is influential only when that individual has a certain level of conscientiousness. This possibility would entail multiplicative associations among personality traits within individuals and potentially between individuals. Additionally, other personality traits may interact with conscientiousness and affect health processes. Neuroticism has been shown to be a strong predictor of mortality and disease (Jerram & Coleman, 1999; Roberts et al., 2007). Specifically, neuroticism is associated with increases in worry and anxiety that may have detrimental effects on the immune system (Kiecolt-Glaser, McGuire, Robles, & Glaser, 2002). Moreover, neuroticism and increases in neuroticism are known to predict mortality in old age (Mroczek & Spiro, 2007). However, some evidence suggests that neuroticism could also have beneficial effects. For example, being anxious about one’s health may lead to activities that promote good health and safeguard against poor health (Lee, Wadsworth, & Hotopf, 2006). Because neuroticism could be beneficial if it led people to be more attuned to and responsible for their health, we hypothesized that being both high in conscientiousness and high in neuroticism could enhance one’s health. The open question was whether the health of one’s spouse also benefits. In the present study, we tested these hypothesized pathways using data from the HRS. First, we tested for a direct effect of conscientiousness on health. Next, we investigated the idea of compensatory conscientiousness by testing whether the conscientiousness of a participant’s partner predicted the participant’s self-reported health above and beyond the participant’s own conscientiousness. In order to account for the interdependencies within couples and to determine the unique effects of each partner, we used the actor-partner interaction model (APIM; Campbell &Kashy, 2002; Kenny, Kashy, & Cook, 2006). The APIM examines the influence of each participant’s personality on his or her own health (actor effect), as well as the effect of the personality of the actor’s spouse on the actor’s health (partner effect). We then tested for a synergistic effect between partner and actor conscientiousness. We also tested both actor and partner effects of neuroticism on health. To test whether being both high in conscientiousness and high in neuroticism leads to better health, we tested the interaction between actor neuroticism and actor conscientiousness. We also tested for an interactive effect of partner neuroticism and partner conscientiousness on the actor’s health.