This book takes a fresh look at the underappreciated role of human psychology in cybersecurity and IT management, discussing the role of cognitive bias and human factors on critical decisions. Written by an experienced CISO and an academic with over two decades of lived experience dealing with cybersecurity risks, the book considers the psychological drivers and pitfalls of the four key personas in cybersecurity - from hackers and defenders, to targeted individuals and organisational leaders. It bridges state-of-the-art research findings with real-world examples and case studies to show how understanding the psychological factors in cybersecurity can help people protect themselves and their organisations better. Full of advice on security best practices that consider the human element of cybersecurity, the book will be of great interest to professionals and managers in the cybersecurity domain, information technology and risk management. It will also be relevant to students and those aspiring to grow in this field.