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or health changes (Magee et al., 2013; Morack et al., 2013; Tolea, Costa et al., 2012; Turiano et al., 2012). In contrast, Agreeableness may play a more meaningful role with regard to health. For instance, lower Agreeableness was found to be associated with faster accumulation of morbidity, as assessed by a physician, over time (Chapman et al., 2013). However, with respect to subjective health outcomes, Turiano et al. (2012) reported that higher Agreeableness scores as well as increases in Agreeableness over time were prospectively associated with lower self-rated health. Together with Neuroticism, Conscientiousness may be the most important health predictor (Reiss, Eccles, & Nielsen, 2014; Shanahan, Hill, Roberts, Eccles, & Friedman, 2014). Specifically, higher Conscientiousness was found to be associated with a lower prospective risk of “getting sicker” as well as with lower future disease burden (Sutin et al., 2013). Additionally, higher Conscientiousness also predicts lower physician-assessed illness burden accumulation over time (Chapman et al., 2013). Moreover, individuals with higher baseline Conscientiousness as well as with increases in Conscientiousness over time were found to report better subsequent self-rated health (Human et al., 2013; Magee et al., 2013; Turiano et al., 2012).
Personality as an Outcome of Health However, a one-sided perspective, focusing on personality as a determinant of health, may not fully capture the complexity of the longitudinal personality-health interface. Health deterioration and the onset of an illness may considerably challenge personality stability. For instance, the experience of health restrictions may upset individuals and complicate the engagement in social and other activities, consequently leading to tendencies of social withdrawal and avoidance of new experiences which may be too exhausting once health is compromised. Thus, poor health may result in an increase in Neuroticism as well as a decrease in Extraversion and Openness to Experience. In addition, severe health problems may also challenge an individual’s capacity to maintain a certain level of Agreeableness, e.g., due to feelings of envy with regard to others’ (better) health. Although the overwhelming majority of empirical studies has considered personality an antecedent of health, there is also some evidence in favor of meaningful health effects on later personality. For instance, the onset of chronic disease was found to be associated with an increase in Neuroticism and a decrease in Extraversion, Openness, and Conscientiousness (Jokela, Hakulinen, Singh-Manoux, & Kivimäki, 2014). Sutin et al. (2013) observed that an increase in illness burden was associated with a decrease in Openness and – though only marginally significantly – with a decline in Extraversion. Similarly, in a sample of very old adults, higher self-reported disability emerged as a risk factor for declines in Extraversion and OpenGeroPsych (2017), 30 (1), 5–17
M. Wettstein et al.: Personality and Health
ness (Wagner et al., 2015). Finally, turning to specific health conditions, the experience of late-life sensory impairment (i.e., vision or hearing loss) seems to be associated with an increase in Neuroticism (Lißmann, 2003), and hearing impairment is related with steeper declines in Extraversion (Berg & Johansson, 2014; Lißmann, 2003). To summarize, personality (particularly Neuroticism and Conscientiousness) seems to meaningfully predict health outcomes, but there is also some evidence pointing at the role of health as a predictor of personality change. However, there is still a lack of studies that simultaneously investigate both directions of the personality-health interface instead of (or in addition to) considering personality as only a determinant of health.
Are Objective and Self-Rated Health Differentially Related with Personality? So far, many studies investigating personality-health associations have focused either on self-rated or on objective/physician-rated health. However, the strength and direction of associations may vary according to whether self-rated or objective health is considered. It seems that Neuroticism, for instance, is more strongly related with self-rated than with objective health (Israel et al., 2014), and the relationship between Neuroticism and self-rated health also holds when controlling for objective health indicators (Duberstein et al., 2003). As another example, Agreeableness was found to be a protective factor for later objective health as rated by a physician in one study (Chapman et al., 2013), but in another study in which health was assessed by self-reports, Agreeableness turned out to be a negative predictor (Turiano et al., 2012). Generally, correlations between indicators of self-rated and objective health are far from deterministic (French, SargentCox, & Luszcz, 2012; Pinquart, 2001), which implies that selfrated and objective health represent empirically distinguishable constructs. The discrepancy between these both health modalities seems to increase with advancing age (French et al., 2012; Pinquart, 2001; Schnittker, 2005). A reason for this discrepancy could be that different factors predict self-rated vs. objective health, and personality might be one of these factors. Specifically, self-rated health may be more strongly influenced and predicted by personality than objective health. Indeed, most of the studies which examined personality effects on later health considered self-rated rather than objective health (e.g., Löckenhoff et al., 2012; Magee et al., 2013). In contrast, though evidence regarding the effects of health on personality change may still be too scarce for firm conclusions, personality may rather change in reaction to objective health conditions (such as sen© 2017 Hogrefe