This chapter introduces the book and the fact that it is motivated by a belief that theories of economic development can move beyond the generally known factors and mechanisms of such development, with the aim being to analyse deeper and more fundamental causes of uneven development. In particular, influences such as innovation, entrepreneurship, knowledge, and human capital are widely acknowledged as key levers of development. However, what are the sources of these factors, and why do they differ in their endowment across places? This chapter indicates that the book seeks to theoretically argue and to empirically illustrate that differences in human behaviour across cities and regions are a significant deep-rooted cause of uneven development. Fusing a range of concepts relating to culture, psychology, human agency, institutions, and power, it proposes that the uneven economic development and evolution of cities and regions within and across nations are strongly connected with the underlying forms of behaviour enacted by humans both individually and collectively.