Date Available


Year of Publication


Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation


Arts and Sciences



First Advisor

Dr. Suzanne Segerstrom


Affective intra-individual variability (IIV) and affective psychological flexibility (PF) are both types of within-person variability. Affective IIV is defined as the range of emotions experienced by an individual assessed at multiple time points. PF is defined as the ability to vary one’s responses in a contextually dependent manner in order to appropriately meet situational demands. Currently, there are no comparisons between affective IIV and PF demonstrating how these constructs might be uniquely different from each other. The current study proposed to examine affective IIV and PF in order to establish discriminant and convergent validity, and stability data for each construct. The National Study of Daily Experiences (NSDE) waves 1 and 2, an 8-day daily diary portion of the Midlife Development in the United States (MIDUS I) and MIDUS II surveys was used for this study (n =793 adults completed both waves of the NSDE). Affective IIV was related to higher mean NA and neuroticism, and lower perceived control. Affective PF was related to lower mean NA, neuroticism, and higher mean PA and perceived control. Higher affective IIV was associated with more psychological distress when assessed concurrently at both waves and predicted more psychological distress and physical ill-health 10 years later. Higher affective PF was related to less psychological distress and physical ill-health when assessed concurrently at wave 1 and less psychological distress and physical ill-health 10 years later. When situational context is included in the calculation of emotional variability, changes in emotional response may represent emotional complexity and increased control rather than emotional lability and are related to better psychological and physical outcomes.