This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book considers the means by which lizards go about achieving and regulating their preferred body temperature, and how such behavior influences other aspects of their behavioral repertoire. It explains how the physical environment affects movement and distribution patterns, including that of dispersion across the landscape. The chapter explores the importance of studying lizards to gain a more complete understanding of the physiological control of social behavior. The relatively poor representation of lizard species studied from the perspective of the physiological control of social behavior stands in stark contrast to the phylogenetically rich and diverse coverage of their display behavior. The chapter shows that research conducted over the last 30 years has revealed that such aggregations are both functionally and phylogenetically diverse among them. It discusses Human-induced rapid environmental change and its impacts on lizards and lizard populations.