Nick Haslam is Professor of Psychology at the University of Melbourne, Australia. He received his PhD in clinical and social psychology from the University of Pennsylvania, and previously taught at the New School for Social Research in New York City. Nick’s research interests include mental health, stigma, and dehumanization and he has published over 250 scholarly articles and book chapters on these and other topics.. In addition to this volume he has published several other books, including Introduction to the Taxometric Method, Values and Vulnerabilities: The Ethics of Research with Refugees and Asylum Seekers and Psychology in the Bathroom. Luke Smillie is an Associate Professor of Psychology at the University of Melbourne and director of the Personality Processes Lab. He received his PhD from the University of Queensland and completed postdoctoral research fellowships at the University of London. He has published over 100 journal articles and book chapters on a range of topics in personality, including neurobiological and motivational accounts of individual differences, the correlates and consequences of extraversion and other basic traits, and the links between personality and social behaviour. He is an Associate Editor at both the Journal of Personality and the Journal of Personality and Social Psychology: Personality Processes and Individual Differences.