A lifespan perspective on daily well-being: Differences in within-person variability by well-being domains and age

To better understand age-related processes tied to well-being, the current work explores how fluctuations in well-being in daily life differ based on age and various well-being domains. Additionally, this research investigates whether the magnitude of concurrent within-person changes in well-being domains varies based on age. Accordingly, the present study called upon daily diary data from two age-diverse samples: a young adult sample (N = 144; age: M = 19.56, SD = 2.09, range = 17-28) and older adult sample (N = 81; age: M = 69.04, SD = 9.06, range = 55-94). Mixed effect location scale models suggested that older adults on average scored higher than young adults on daily self-acceptance, engagement, sense of purpose, autonomy, competence, personal growth, relatedness, vitality, and positive affect; scored lower on negative affect; and did not score differently on life satisfaction. Meanwhile, young adults experienced more daily within-person variability in all 11 well-being domains. Finally, multigroup, multilevel structural equation models showed that, at the between-person level, negative affect was more strongly tied to other well-being domains in young adults, while positive affect and vitality were more strongly tied to other well-being domains in older adults. At the within-person level, changes in one daily well-being domain were more strongly associated with changes in another 65% of the time for young adults and 33% of the time for older adults. The present study highlights differences in daily well-being processes tied to age and the larger role that daily events and experiences may play in shaping the short-term experiences of well-being in young adults' daily lives. (PsycInfo Database Record (c) 2026 APA, all rights reserved).