Across multiple domains of psychology, resilience is a well-researched construct. However, the research literature has been hampered by ambiguities and inadequate in its conceptualisation, assessment, and impact. With these issues in mind, we first offer a comprehensive model of resilience drawn from its contemporary conceptualisations. Second, we develop a self-report resilience measure from this model. Finally, we aimed to test this resilience model and assessment in challenging settings with young people who participate in overseas expeditions. Unfortunately, due to the COVID-19 pandemic, we could not fully utilise these expeditions. Therefore, we further examined and tested our resilience model to another challenging scenario, the pandemic itself.

The thesis comprises six empirical studies organised into three chapters. Chapter 1 takes a critical examination of resilience research, highlighting several limitations we perceived. These included (i) ambiguous and incomplete resilience definitions and conceptualisations; (ii) associated problems with measurement (alongside problematic psychometric properties); and (iii) lack of theory-driven intervention tools and studies. Chapter 1 supports and extends resilience as a state-like, pro-active and reactive response containing the mechanisms of anticipation, minimising, managing, and mending. We also support and extend research where mechanisms can operate in several domains of life, including physical, social, cognitive, emotional, and a general domain. The chapter finishes by discussing applications for this model in expeditions research, interventions, and profiling.

Chapter 2 contains two separate studies aimed at developing a resilience measure in line with our conceptualisation. Study 1 (n = 181) focused on establishing the measure (the Resilience Process Scale, RPS), with items based on the four mechanisms of anticipate, minimise, manage, and mend, with vignettes to separate each domain (general, physical, social, cognitive, & emotional). We used Bayesian Structural Equation Modelling (BSEM) to validate the model and refine the scale into a 13-item measure (using the same 13-items in each domain or vignette). Study 2 (n = 284) further validated the measure using BSEM and a more heterogeneous sample, providing further support for the factorial validity of the RPS.

Chapter 3 contains two separate studies. Study 3 (n = 35) examined overseas expeditions as a challenging environment that could enhance resilience mechanisms and domains. Study 4 (n = 16) focused on an expedition training weekend to examine the benefits of training and to design and pilot test a theory-driven resilience intervention. The intervention introduced challenges to target the five domains of resilience via evidence-based strategies. The main findings across the studies indicated that expeditions and training weekends provide an environment that enhances resilience, cognitive appraisals, and well-being, in addition to positive correlations between resilience mechanisms with positive self-concept and well-being. However, probably due to the small sample size and an incident that developed over the weekend, there were no significant effects of the intervention.

Chapter 4 contains two separate studies. Using data from studies 1-4, Study 5 (n = 555) examined resilience profiles across the four mechanisms using Latent Profile Analysis, revealing four emerging profiles. Study 6 provided confirmation of the replicability of these profiles in a new sample (n = 400). We examined the relationship between the profiles across different cognitive, affective, and behavioural outcomes in relation to the pandemic. We further explored the stability of resilience profiles over a four-month period. The main findings included confirming four profiles: 1. Low resilience – High anticipate. 2. Low resilience – Low anticipate. 3. Moderate resilience. 4. High resilience. Further, resilience is related to greater well-being, coping, and lower anxiety. The profiles were also somewhat replicable with stability across time.

Chapter 5 concludes the thesis, providing a general summary and discussion of the findings, implications for theoretical and applied perspectives, and paths for future research.