Henri Tajfel's interest in identity and group prejudice was sparked by his own experiences as a Polish Jew during the Second World War. As Professor of Social Psychology at Bristol university he developed a series of experiments known as the Minimal Group Studies
Stephen D Reicher (Steve Reicher) is Professor of Social Psychology and former Head of the School of Psychology at the University of St Andrews, Scotland, UK. In this short clip he talks about "group hatred" referring to examples of Nazi Holocaust and Hindu Extremism.