Negative affectivity and biological health in Japan and the United States

We start with recent evidence documenting a relevant cultural variation. This evidence focuses on neuroticism – a global personality trait defined by negative affectivity. Although this trait is widely regarded as maladaptive in the current literature (Friedman & Kern, Reference Friedman and Kern2014), this consensus may be premature. Neuroticism may be adaptive or maladaptive, depending on how readily people are willing and able to adjust their behaviors and preempt the existing threat, which this personality trait highlights and thus amplifies (Kitayama et al., Reference Kitayama, Park, Miyamoto, Date, Boylan, Markus and Ryff2018). If people are relatively high in behavioral adjustment, they can change their behaviors to cope with the threat. Hence, the sensitivity to the threat, enhanced by neuroticism, can be adaptive. However, if they are unable or unwilling to adjust their behaviors, they may be overwhelmed by the threat, especially if it is magnified by high neuroticism. In a recent study, Kitayama et al. (Reference Kitayama, Park, Miyamoto, Date, Boylan, Markus and Ryff2018) tested how neuroticism might be associated with a biological health risk in a large sample of adults in interdependent and independent countries (Japan vs. the United States) while assessing this risk with biomarkers of inflammation and cardiovascular malfunctioning. They also measured behavioral adjustment with a rating scale.

This study found a significant behavioral adjustment × neuroticism interaction, which indicates that neuroticism is adaptive for those relatively high in behavioral adjustment. However, the effect of neuroticism was reversed for those low in behavioral adjustment. Moreover, consistent with the proposition that Japanese culture values interdependence with others and thereby positively sanctions behavioral adjustment, but American culture does not (Markus & Kitayama, Reference Markus and Kitayama1991), Japanese were significantly higher in behavioral adjustment than Americans. Correspondingly, neuroticism was associated with a decreasing biological health risk among Japanese. However, this effect disappeared for Americans. Importantly, among a subset of Americans who were particularly low in behavioral adjustment, neuroticism was associated with a significant increase in biological health risk. The conclusion that negative affect can be adaptive in an interdependent society has been corroborated in other studies (Kitayama et al., Reference Kitayama, Park, Boylan, Miyamoto, Levine, Markus and Ryff2015; Miyamoto et al., Reference Miyamoto, Boylan, Coe, Curhan, Levine, Markus and Ryff2013; Park, Kitayama, Miyamoto, & Coe, Reference Park, Kitayama, Miyamoto and Coe2020). Contrary to Grossmann's speculation, the putative adaptiveness of negative affectivity (and thus fearfulness) is not limited to small-scale societies.

Cultural evolution

To fully understand the above evidence, we must consider how culture has evolved over the last 10,000 years. Grossmann is perhaps right that hunting-and-gathering small-scale societies were closely knit and centered around kinship. That is, they were interdependent. The emphasis on interdependence, however, continued even after humans began sedentary living aided by farming and herding approximately 10,000 years ago. Since then, larger communities emerged as farming became supportive of larger populations. Such communities turned into big cities and kingdoms. Along the way, different regions developed strikingly different forms of interdependence. For example, interdependence can be supported by self-effacement, as in East Asia, where the hegemonic culture was supported by rice farming (Talhelm et al., Reference Talhelm, Zhang, Oishi, Shimin, Duan, Lan and Kitayama2014). It can also be supported by self-assertiveness, as in Arab regions, where the hegemonic culture recognizes a dire need to protect ingroups against outgroups (San Martin et al., Reference San Martin, Sinaceur, Madi, Tompson, Maddux and Kitayama2018). Although these two cultures seem diametrically different at first glance, they are similar in one respect. Both cultures share a strong commitment to interdependence within ingroups.

All of this began to change in the Western corner of the Eurasian continent over the last 1,000 years, with a radical change occurring in how people understood themselves and their world (Kitayama et al., Reference Kitayama, Salvador, Nakakdewa, Rossmaier, San Martin and Savaniin press). This change, perspectival in nature, was precipitated by numerous historical happenstances and developments, including the reformation and enlightenment (Taylor, Reference Taylor1989; see also Schulz, Bahrami-Rad, Beauchamp, & Henrich, Reference Schulz, Bahrami-Rad, Beauchamp and Henrich2019). It has gradually defined the Modern West – a cultural tradition organized by the model of the self as an agent independent from others. Perhaps for the first time in human history, the independent model of the self became hegemonic, linked to wealth and power. This trend may still be underway (Varnum & Grossmann, Reference Varnum and Grossmann2017).

Before the Modern West, people defined themselves while referring to the group they were part of. They saw themselves and understood the world while taking the group's perspective. Consequently, it was satisfying to “be appreciated” or “honored” by others. Adjustment and conformity to group norms were the default. However, people in the Modern Western traditions began understanding the self and the world from their perspective. Consequently, social acknowledgments, such as appreciation and honor, while desirable, were no longer fully satisfying. Instead, it became imperative for people to affirm their positive selves, which, in turn, commanded others' respect and admiration. One consequence was a strong insistence on holding fast to the self's values and goals at the expense of social expectations. Freedom became valued and prioritized over conformity, which explains why the behavioral adjustment is lower (which rendered negative affectivity a major health risk) among European Americans today compared to Asians and perhaps other non-Westerners (Schulz et al., Reference Schulz, Bahrami-Rad, Beauchamp and Henrich2019).