Contributor(s): Professor Peter Ayton, Dr Sepideh Bazazi, Professor Chris Frith | In our modern world we are constantly exposed to the opinion of the group. When is the crowd wise and when is it prone to madness? Peter Ayton (@Thruthal) is Professor of Psychology at City University London. Sepideh Bazazi is a researcher at the Centre on Animal Cognition, DYNACTOM, Université Paul Sabatier. Chris Frith (@cdfrith) is a psychologist and Professor Emeritus at the Wellcome Trust Centre for Neuroimaging, University College London. Bahador Bahrami (@bahadorbahrami) is Senior Research Associate at the Institute of Cognitive Neuroscience, UCL. The Forum for European Philosophy (@LSEPhilosophy) is an educational charity which organises and runs a full and varied programme of philosophy and interdisciplinary events in the UK. Credits: Tom Sturdy (Audio Post-Production), LSE AV Services (Audio Recording).