Emotional Reactivity to Daily Stressors: Does Stressor Pile-Up Within a Day Matter for Young-Old and Very Old Adults?

Over the past decade, many studies have reported individual differences in negative emotional reactions to daily stressful events. However, whether and how individual and age-related differences in emotional reactivity also depend on the temporal characteristics of stressors has received little attention. In this project, we focused on the temporal characteristics of stressor occurrence and examined the pile-up of stressors within a day-referring to multiple stressors encountered within a relatively narrow time window. To do so, we used data from 123 young-old (66-69 years, 47% women) and 47 very old adults (84-90 years, 60% women). Participants reported their momentary feelings and exposure to stressors six times a day over 7 consecutive days in their everyday life. Emotional reactivity to stressor pile-up over the day followed an exponential decay trajectory, with higher stressor burden in close proximity to the stressor occurrence. The exact shape of the decay trajectory differed among participants. Most importantly, both stressor pile-up and ongoing stress predicted greater emotional reactivity. We also found interaction effects of stressor pile-up and current stressor occurrence in that increases in negative affect under ongoing stress were stronger when stressors had piled-up before. No evidence was found for increased vulnerability to stressor pile-up in very old adults; rather, the impact of preceding stressors attenuated faster for individuals in this age group. The findings highlight the utility of comprehensively studying how stressor characteristics such as their pile-up within short time periods shape emotional reactivity.