Date of Award


Degree Type


Degree Name

Doctor of Philosophy in Psychology



First Advisor

Lisa Harlow


Statement of the problem: Positive psychology research has sought to identify cost efficient and intuitive ways to increase subjective happiness, with broad implications to personal health and overall quality of life (Lee Duckworth, Steen, & Seligman, 2005; Rashid, 2009; Seligman, 2008; Seligman, Ernst, Gillham, Reivich, & Linkins, 2009; Seligman, Rashid, & Parks, 2006). A complication in this research has been conflicting findings in the longitudinal stability of happiness (Easterlin, 2006). This analysis examines age related changes in happiness and physiological immune responsiveness to clarify the implications of positive health interventions.

Methods: Pretest-posttest structural equation modeling is employed to examine longitudinal association. Data from the Longitudinal Aging Study Amsterdam are analyzed (Hoogendijk et al, 2020). Operationalizations of two theories of happiness as well as interleukin-6, a measure of physiological inflammation, are considered. Associations are examined between baseline rates and changes at follow-up. In addition to estimating associations among the primary outcome variables, age is also included as a predictor, in addition to possible confounds.

Summary of results: Consistent with hypotheses, significant positive associations were identified among changes in happiness and inflammation response. Conversely, relationships with age were nonsignificant or directionally opposite from the positive association identified in previous literature. It is suggested that while lifelong deterministic trends in subjective experience and inflammation may plateau during older adulthood, the variables may still demonstrate meaningful association. This analysis provides a methodically rigorous comparison of two leading theories of subjective well-being. It is concluded that feelings of social support and connection may mitigate some of the challenges faced by older adults, such as the mortality of friends and family. Further, this could help older adults facilitate positive aging and longevity.



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