Thriving under challenges – establishing individual and situational influences on eustress

Across four projects, I aimed to develop an in-depth understanding of how individuals experience eustress–the positive experience of a challenging situation. Specifically, I aimed to understand how eustress manifests in UK adults in general and in specific real-life situations. In Project 1, I performed a scoping review and deductive theory building to integrate 57 unique features of eustress from 80 articles into a Comprehensive Hierarchical construct of Eustress (CHE). According to CHE, eustress emerges from three main sources: successful goal-directed action, fulfilling momentary experiences, and positive stable qualities of the individual. In Project 2, I developed and assessed a novel eustress instrument, the Comprehensive Hierarchical Eustress Review (CHER), reflecting CHE’s content and structure. In a quantitative study (N = 260), I found that the CHE model adequately described eustress in UK adults and provided insights into its relationships with distress and wellbeing. In Project 3, I established feature profiles of 20 difficult situations that likely induce eustress. I found that as UK adults (N = 81) judged a situation as increasingly threatening and challenging, they also judged it as more difficult and effortful with a less obvious solution and less effective coping. I found that a large language model could approximate general trends in human judgments but failed to reproduce meaningful relationships in the data. In Project 4, I combined insights from the previous projects to establish predictive profiles of eustress and explored how these profiles varied across individuals and real-life situations. In a quantitative survey (N = 251), I found that eustress emerges from individual-situation interactions, is predicted by the underlying processes of the CHE model and is weakly related to adaptive stress mindsets. I discuss the implications of my research regarding eustress theory development and measurement, as well as applied implications, limitations, and future directions for eustress research. By establishing a comprehensive construct of eustress and testing it across individuals and situations, this thesis may help formalize the small but growing research field on positive stress. Eustress is a complex behavior that is shaped by individual (e.g., fulfilment coping) and situational (e.g., intrinsic difficulty) processes as well as their interactions. I suggest that this research can be used to establish who experiences eustress under what circumstances, and what strategies are most effective in fostering positive stress where desirable and applicable.