How personality moderates stress in needs thwarting environments

Individual stress responses have been addressed by multiple theorists; yet there remains uncertainty concerning how contextual and individual factors interact during the process. In this thesis, I formulate and test a transtheoretical model integrating basic psychological needs (Deci & Ryan, 2002) theory and challenge and threat states (Blascovich, 2008) to better understand when and why environments might differentially affect appraisals. In contrast to previous work theorising a deterministic relationship between thwarting environments and threat appraisals, I hypothesized that in presence of needs thwarting, specified personality factors exacerbate or attenuate sensitivity to stress, and subsequent formation of challenge and threat-based appraisals. The model was tested across two experimental studies where needs thwarting was elicited: in Experiment 1 students (n=54) led an academic presentation. Psychometric and cardiovascular data confirmed some support for the moderating influence of personality: only extraversion significantly moderated the stress reaction, though perceived relatedness frustration was poorly affected by manipulation. Experiment 2 therefore replicated this protocol on athletes (n=18), separating the effects of competence and relatedness thwarting. Relatedness manipulation was enhanced using real friendship groups and providing fake feedback regarding group rejection. However, perceived relatedness frustration remained low, and the study was suspended due to manipulation failure. In response, I conducted a scoping review to critically assess protocols for acute manipulation of relatedness. This identified critical gaps regarding explicit testing of relatedness thwarting and concerns about protocol effectiveness. More promisingly, imagery/recall and ostracism-based protocols were effective and highlighted the utility of drawing from non-SDT based research. The review informed the generation of a set of recommendations for researchers seeking to manipulate relatedness in future work. This doctoral thesis contributes to the understanding of the interplay between environment and individual differences in stressful environments and offers methodological evidence to improve the study of these dynamics, with a specific focus on relatedness-thwarting settings. I argue that these ideas and methods will enhance understanding of individual reactions to socially-challenging environments, and identify protective factors associated with resilience and growth.