Intraindividual Variability in Positive and Negative Affect Over 45 Days: Do Older Adults Fluctuate Less Than Young Adults?

Opposing scenarios about age-related increases and decreases in intraindividual variability are found in the literature: Whereas accumulating evidence indicates that cognitive functioning is characterized by an age-related increase of short-term variability, age-related decreases in variability could be expected in affective states on the basis of theories of emotion regulation and self development. We examined age differences in intraindividual variability of positive affect (PA) and negative affect (NA) and in contingencies among daily affect, daily stress, and daily events using up to 45 daily assessments of 18 young (20-30 years) and 19 older (70-80 years) adults. Whereas age groups differed little in average affect levels, older adults showed significantly less variability in PA and NA than young adults. Age differences accounted for greater variance in variability than personality factors. Multilevel modeling indicated that for young but not older adults, PA was higher (lower) on days with a positive (negative) event, and NA was lower on days with a positive event. There were no age differences in daily affect reactivity to appraised stress severity.