This book applies multilevel selection theory to an examination of both the natural history of ideology, and how that natural history has unfolded through the course of civil history in the Western world. Its authors bring together research from across the fields of history, political science, genetics, neurobiology and social science to offer an unprecedented synthesis.

Addressing natural history, Part I evolutionarily explains why political ideology is substantially genetic, correlates with personality traits, and is represented in brain regions associated with risk and emotional processing. Addressing civil history, Part II traces the evolution of political ideology across anthropological transitions from non-human primates to small-scale societies, and across historical transitions from autocratic states through to democratic societies with political parties peaceably transferring power and tolerating opposition. In this way, its authors aim to demonstrate that temperamental antecedents to political ideology that are biologically derived, evolutionarily explicable, and historically palpable.

This book presents timely insights into issues the evolutionary history of hyper-partisanship that will be of interest to scholars across the fields of political science, political psychology, evolutionary psychology and history.