The present dissertation offers a big data window into the causes and consequences of geo- graphical differences in personality. After an initial introduction to the field and a broad over- view of the relevant literature (Chapter 1), I present an applied tutorial, that describes the typical analytical process when addressing psychological research questions with spatial data (Chapter 2). In the following two chapters, I investigate the consequences of geographical personality differences on the regional macro- and individual micro-level. On the macrolevel, Chapter 3 demonstrates how regional courage (based on 513,224 individual responses) can explain the high suicide rates in the Mountain West of the US. On the micro-level, Chapter 4 links regional estimates from a UK-wide personality dataset (n = 368,375) to individual personality and spending records (31,915,942 transactions) to show that regional personality determines individual spending, regardless of and sometimes with the same magnitude as individual personality. Shifting the focus onto the causes of geographical personality differences, in Chapter 5 and 6, three empirical studies shed light on different mechanisms that may contribute to spatial differences in psychological characteristics. To that end, I first consider the effects of natural and built environments on personality, by investigating physical topography in relation to personality across a sample of 3,387,014 US residents (Study 5.1) and by investigating neighbourhood design in relation to personality across a sample of 5,141 Japanese residents (Study 5.2). Second, examining the role of economic conditions, I employ time-series models to show how local economic development predicts rising Openness levels across 199 US cities, which are monitored over a period of nine years. The dissertation concludes with a final chapter which embeds the current efforts into the broader literature, dis- cusses their limitations, identifies overarching challenges and opportunities in geographical psychology and presents a preliminary process-model (GEO-PSY-PROMO) which may guide future research.