Happy Like a Fish in Water? The Role of Personality–Situation Fit for Momentary Happiness in Social Interactions across the Adult Lifespan

Growing research on personality–relationship dynamics demonstrates that people's personality and their (enjoyment of) social relationships are closely intertwined. Using experience sampling data from 136 adults (aged 18–89 years) who reported on more than 50 000 social interactions, we zoom into everyday real‐world social interactions to examine how Big Five personality traits and social context characteristics shape people's happiness in social encounters across the adult lifespan. Results revealed that interactions that were social (vs. task‐oriented) and with close (vs. less close) others were associated with higher momentary happiness as were higher levels of the target person's extraversion, agreeableness, and conscientiousness, and lower neuroticism. Of the 10 personality × situation interactions tested, only one reached significance (with p = .041): Individuals with higher levels of neuroticism benefitted more from interactions with friends than did individuals low in neuroticism. The role of social context characteristics for momentary happiness changed with age, but the role of personality or personality × social context did not, suggesting that personality effects on happiness in social context manifest in similar ways across the adult lifespan. We discuss implications for personality–situation research and the understanding of affective dynamics in everyday social interactions. © 2019 European Association of Personality Psychology