is head of the Centre for Interdisciplinary Memory Research at the University of Essen and Research Professor of Social Psychology at the University of Witten/Herdecke. His publications include Opa war kein Nazi. Nationalsozialismus und Holocaust im Familiengedächtnis [Grandpa wasn’t a Nazi. National Socialism and Holocaust in family memory] (2002); Täter. Wie aus ganz normalen Menschen Massenmörder werden [Perpetrators. How completely normal people become mass murderers] (2005); Klimakriege. Wofür im 21. Jahrhundert getötet wird [Climate wars. What will be killed for in the 21st century] (2008); and, together with Claus Leggewie, Das Ende der Welt, wie wir sie kannten. Klima, Zukunft und die Chancen der Demokratie [The end og the world as we know it. Climate, the future and chances for democracy] (2009).