Jens Weidner has been Professor of Victimology & Criminology at the Hamburg University of Applied Sciences at the Faculty of Economic and Social Affairs since 1995. After studying social sciences with an emphasis in criminology in Lüneburg, Tübingen and Philadelphia, Jens started working with gang members from New York, Washington and Philadelphia in the Glen Mills School, USA. From 1987 to 1995, he developed the Anti- Aggression Training ® for violent repeat offenders and used it at the youth prison Hameln in Germany. In 1991, he received his PhD with the subject: Anti- Aggression Training for violent offenders. From 1993 - 2000 he worked on the development and implementation of the certified training for anti - aggressiveness and as coolness ® coach at the Institute for Social Work and Social Education in Frankfurt and from 1994 - 2012 he was management trainer at the Swiss Gottlieb Duttweiler Institute for Economic & Society in Zurich, on the subject: Assertiveness for managers. Since 2012 he is trainer at the Schranner Negotiation Institute in Switzerland. He also offers anger management seminars and service management training, in collaboration with the theatre and television actor Lutz Herkenrath. Since 2005 he is co-owner of the German Institute for Confrontational Pedagogy and since 2007, initiator of the annual " Excellence Award Social Work " award by the HAW -Hamburg , the Hamburg 13 LIONS clubs and Siemens. His business book "The Pepperoni Strategy: How you use your natural aggression constructively " was published in 2005 and was number 1 of the bestseller rankings of the Financial Times Germany for 33 weeks and has now also been published in Korea, Taiwan, Poland, Spain and Russia. In 2008, he received the Speakers Excellence Award in Munich and his “pepperoni- strategy” has received the distinction as a career strategy classic .