Psychology - and life - do not happen in a vacuum. Every behaviour we study happens in a political, economic, socio-cultural, and physical context that is shaped by geography. Put differently: where we are matters for who we are, whom we meet and whom we identify with. Based on this premise, the geo-psychological literature investigates the composition, causes and consequences of spatial variation in personality. The research presented in this thesis aims to better understand our behaviour by adopting a lens that incorporates information on who we are and where we are. After giving a general introduction in Chapter 1, I will look at methodological barriers hindering the wider adoption of geo-psychological approaches, especially regarding data access and data processing. A novel crosswalk that can alleviate this problem is introduced in Chapter 2. In addition to providing a theoretical framework of how methodological barriers can be overcome, the crosswalk presents a practical tool that allows psychologists, as well as researchers from other disciplines, such as economics and sociology, to merge the personality data effortlessly into their existing datasets. Next, two geo-psychological applications in the health sector are introduced, which are based on the Big Five personality construct (Chapter 3-4): Chapter 3 adopts a psycho-social model to investigate spatial prescription patterns by analysing England’s largest personality survey and 4.1 billion general, 95 million anxiety-specific, and 178 million depression-specific prescriptions issued in England between 2015 and 2019. Chapter 4 looks at 54 countries’ reactions to the COVID-19 pandemic and shows the influence of personality and government stringency on our behaviour. While the aforementioned empirical projects utilise a geo-psychological lens to understand the influential consequences of differences in Big Five personality traits, Chapter 5 looks at an alternative construct - the Schwartz Human Values. The work is of psychometric nature and shows how values develop throughout the lifespan, across three hierarchical levels. A particular focus is put on predictive power and its limits for practical applications. Chapter 6 finishes with a general discussion of my research, which highlights the interplay between who and where we are and establishes novel frameworks that can be applied in future research to push our understanding of individual differences in the context of the environment we live in.