Emotion, Vol 26(5), Aug 2026, 1058-1072; doi:10.1037/emo0001654
Positive affect has been linked to better sleep. However, this evidence primarily comes from Western societies with a long-standing cultural tradition of prioritizing the pursuit of positivity. Here, we tested whether such benefits generalize to East Asian societies, where positive affect is less culturally valued. In these cultural contexts, individuals strive to achieve emotional balance, and thus, elevating positive emotions may not confer the same health benefits. We tested this hypothesis in two cross-cultural studies. Using large-scale surveys from American and Japanese midlife adults (N = 1,358), Study 1 examined whether culture moderates the relationship between positive affect and subjective sleep quality. As predicted, higher positive affect was associated with better subjective sleep quality among European Americans, but not among Japanese. Study 2 employed a 2-week daily diary design to examine whether European American and East Asian college students (N = 119) differ in how positive affect relates to both subjective and actigraphy-derived sleep measures. Among European Americans, higher average positive affect was associated with better subjective sleep quality and a calmer (vs. tense) mood upon awakening. By contrast, these associations were not observed among East Asians; instead, greater positive affect predicted shorter sleep duration for these individuals. Notably, these cultural differences emerged only for high-arousal (not low-arousal) positive affect. Together, these findings suggest that the restorative benefits of positive affect on sleep may be culturally contingent, depending on how positive emotions are viewed in different societies. (PsycInfo Database Record (c) 2026 APA, all rights reserved)