The human brain faces a set of dilemmas every day: how to achieve coherence from fragmented sensory inputs and how to attain connection with other people in an increasingly atomized and isolating world. Ideologies offer a shortcut, providing easy answers, scripts to follow, and a sense of shared identity. Whether our ideologies are far-right, far-left, nationalist, religious, or even progressive, they simplify our understanding and give us organizing frameworks through which to act and interact with others. But ideologies come at a cost: demanding conformity and suppressing individuality through rigid rules, repetitive rituals, and intolerance. Once ideologies grip our minds, they fundamentally transform us, making us less sensitive and adaptable. Drawing on her groundbreaking research, Dr Leor Zmigrod uncovers the hidden mechanisms driving our beliefs and behaviours. She uses the powerful tools of neuroscience to show that our political beliefs are not transient thoughts in our minds, divorced from our bodies – ideologies actually change our neural architecture, our cells. For instance, she demonstrates how a simple card sorting game can reveal your entire approach to life. Cognitive rigidity in such tasks – struggling to adapt to new rules – mirrors the rigidity with which you cling to social and political ideologies. While some individuals are more susceptible to dogmatic thinking than others, all of us can strive to be more flexible. The Ideological Brain is essential reading in today’s polarized and polarizing world. To foster a more informed, resilient and freer society, we need to zoom into the processes happening inside each of us and learn to spot rigid thinking in ourselves and others. We need to learn to avoid black-and-white thinking and embrace ambiguity. We need to recognize our ability to resist irrational rules and authority. Regardless of your political stance, this book will challenge you to reassess your convictions – and what they are doing to your brain.