My intention for this thesis was to explore the factors that contribute to mental toughness development by considering the perspectives of individuals during critical stages of personal growth, and to embed such understandings within established theories from broader fields of psychological enquiry. Initially, I explored the innate and environmental factors that adolescents believed contributed to mental toughness, as well as attempted to ground such knowledge within an established theory from broader fields of psychological enquiry. I recruited eighteen adolescents (9 boys, 9 girls, Mage = 15.6 years) with a ‘reputation’ of mental toughness and invited them to participate in focus group interviews. Seven of these adolescents also participated in follow-up 1-1 interviews. Both focus groups and 1-1 interviews began with questions pertaining to the conceptual components of mental toughness (e.g., “what allows you to regularly perform to the best of your abilities?”) and its development (e.g., “where did these characteristics originate from?”). Inductive analyses of participants’ perspectives revealed that mental toughness development was predicated by four factors: interactions with significant others, the provision of supportive social processes, exposure to critical incidents, and a personal propensity for curiosity. These findings were interpreted within the context of Bronfenbrenner’s (2001) bioecological model. I concluded that, while my findings were one of the first to advocate for the combined role of innate and environmental factors in the development of mental toughness, it is the latter that is of greatest interest from an applied perspective and should be more closely considered in the future.
Subsequently, I sought to focus my efforts on the environmental factors that contribute to mental toughness development. Although the bioecological model is a useful framework for categorising the factors associated with mental toughness development, it is not easily applied to practice. That is, the framework is more descriptive than practical in nature.
As such, I contested that there was a need to draw on another theory that, although consistent with the bioecological model, possesses strong applied implications. As such, I investigated the utility of Self-determination theory (SDT, Deci & Ryan, 1985b) principles for understanding mental toughness development. I predicted that coaching environments (i.e., autonomy-supportive, controlling) would be related to mental toughness indirectly through psychological needs satisfaction, and that psychological needs satisfaction would indirectly relate with performance and psychological health (i.e., positive/negative affect) through mental toughness. I recruited 221 adolescent cross-country runners (136 male and 85 female, Mage = 14.36) and invited them to complete questionnaires pertaining to their perceived coaching environments, the degree to which their psychological needs were satisfied, mental toughness, and psychological health. Performance was measured by recording athletes’ championship race times. In attending to my hypotheses I analysed my data using Bayesian analysis. My findings supported my hypotheses leading me to conclude that SDT principles are useful for understanding the development of mental toughness. In particular, I surmised that mental toughness and its associated adaptive outcomes are a result of coaching behaviours that promote psychological needs satisfaction.
I sought to build on the findings of my second study by designing a coach-centred intervention, grounded within SDT, with the intention of developing mental toughness in adolescent athletes. I hypothesized that, autonomy-supportive coaching behaviours, psychological needs satisfaction, mental toughness, vitality (an indicator of psychological health), and objective performance, would increase following the intervention. In contrast, I expected that controlling coaching behaviours, psychological needs thwarting, and burnout (an indicator of psychological ill-health) would decrease. Observational, qualitative, and quantitative data related to my hypotheses were collected with coaches (N = 18) and athletes (N = 61) prior to and immediately following an 8-week intervention, as well as 8-weeks following the end of the intervention. My results did not support my hypotheses. Specifically, my results indicated that coaches did not adopt autonomy-supportive behaviours following the intervention. I suggested that this lack of adherence was due to contextual barriers. As this study was, to my knowledge, the first to experimental evaluation of an intervention informed by SDT principles in sport for mental toughness or any other outcome, I provided recommendations for researchers about how to overcome the barriers I encountered when conducting similar interventions in the future.
Based on the findings of my empirical studies, I composed a conceptual essay to summarise key theoretical concepts that I had generated across my research, particularly my final two studies. The aim of my essay was to demonstrate the utility of SDT for understanding mental toughness and its development. In particular, I proposed that SDT provides a sound basis for understanding the motivational antecedents of mental toughness. To achieve my aim, I considered concepts that appeared to bridge mental toughness and self-determination theory literature, namely notions of striving, surviving, and thriving. I concluded this essay with suggestions for future lines of empirical enquiry that could be pursued to further test my propositions.