Title: A Componential Model of Stress Reactivity in Daily Life
Description: Despite widespread agreement about the importance of stress for health and well-being, scholars disagree about the types of variables that matter most. On one side, some argue that stress reactivity depends mostly on person-level variables, such as personality, while others contend that stress reactivity depends mostly on situation-level variables, for example chronicity. Researchers from a more integrative perspective assert that stress reactivity depends on an idiosyncratic interaction between person-level and stressor-level variables, for example the finding that lonely people are especially reactive to interpersonal tension. My dissertation reconciles these perspectives by leveraging crossed random effect modeling to determine the percent of stress reactivity attributable to each of these types of variables; the person, the situation, and the person-by-situation interaction. In Study 1, 368 undergraduate college students reacted to 60 unique situations in the context of normal daily life on two separate occasions.

In Study 2, 955 adults from the Midlife in the U.S. study self-reported their reactivity to stressful situations encountered on each of eight days. Results from both studies suggest that these three types of variables account for the bulk, at least 70%, of stress reactivity in daily life. Moreover, all three types of variables emerged as important, as each factor contributed at least 20% of the overall variability in stress reactivity. Interestingly, both studies also found that situation-level variables mattered relatively more than the other two types of variables. I discuss these findings in relation to stress theory, stress-reduction interventions, and methodological innovations.