When studying for a doctoral degree (PhD), candidates submit a thesis that provides a critical review of the current state of knowledge of the thesis subject as well as the student’s own contributions to the subject. The distinguishing criterion of doctoral graduate research is a significant and original contribution to knowledge.
Once accepted, the candidate presents the thesis orally. This oral exam is open to the public.
Functional approaches to emotion posit that different negative emotions serve adaptive functions by facilitating distinct motivational processes in response to situational demands. The discrete emotion theory of affective aging provides a lifespan developmental framework for examining the age-related fluctuations in the adaptive value of discrete negative emotions across older adulthood. With increasingly stressful life circumstances, the motivational concomitants of anger (i.e. persistence) may become relatively maladaptive, while those associated with sadness (i.e. disengagement) become paramount. This dissertation sought to examine the divergent associations of anger and sadness with motivational processes, emotional well-being, and physical health, and to explore the moderating roles of age and stress. Finally, this dissertation sought to demonstrate the adaptive value of the sadness-disengagement process.
Study 1 investigated the age-related associations between older adults’ anger and sadness with chronic low-grade inflammation (i.e., IL-6 and CRP) and chronic illness using cross-sectional data from 226 older adults. Results suggested that anger, but not sadness, was associated with chronic inflammation and illness in old-old, but not young-old, adults. Further, the age-related association between anger and chronic illness was mediated by chronic inflammation.
Study 2 explored the associations of sadness and anger with goal disengagement capacities, emotional well-being (i.e. positive and negative affect), and stress (i.e. perceived stress, and diurnal cortisol) using 10-year longitudinal data from 184 older adults. The results revealed a within-person association between sadness, but not anger, and goal disengagement capacities among older adults with generally elevated cortisol. Further, older adults who disengaged more when they experienced sadness were buffered from declines in positive affect associated with elevated levels of cortisol.
Study 3 sought to examine the adaptive value of goal disengagement, and its association with depressive symptoms. Using meta-analytic techniques to synthesize 421 effect sizes from 31 samples, the analyses revealed goal disengagement was associated with higher quality of life, particularly in older samples. Further, the association between goal disengagement and lower depressive symptoms was reversed in samples at risk-for depression.
This dissertation integrates theory and research from the fields of emotion, lifespan development, personality, and evolutionary psychiatry, and contributes to the literature on successful aging.