Older people are not always happier than younger people: The moderating role of personality.

The present research explored whether the well-established U-shaped relationship between age and happiness varied with personality. Individuals ranging from 15 to 75 years of age (N = 10,456, 84.9% female) completed online surveys of subjective well-being (i.e. life satisfaction, positive affect, and negative affect) and the Big Five personality traits (International Personality Item Pool [IPIP]). The results of hierarchical multiple regression using the PROCESS macro not only supported the prediction of a U-shaped relationship between age and well-being but also revealed that the quadratic relationship is moderated by agreeableness and neuroticism. Specifically, well-being did not bounce back in later adulthood on the well-being curve across different age groups with low agreeableness and high neuroticism. Moreover, positive affect did not increase and even decreased in later adulthood among those with low agreeableness. This study discusses the potential mechanisms.