Heinz Streib is a senior professor at Universität Bielefeld, Germany, and conducts research in psychology of religion. He established and directs the Research Center for Biographical Studies in Contemporary Religion. He is editor-in-chief of the International Journal for the Psychology of Religion. His research focuses on biographical-reconstructive and psychometric assessment of religious change and development over the lifespan, deconversion, fundamentalism, xenophobia and the semantics of spirituality.Ralph W. Hood Jr. is a professor of psychology, LeRoy A. Martin Distinguished Professorship of Religious Studies at the University of Tennessee at Chattanooga, and UT Alumni Association Distinguished Professor. He is a past president of the Division 36 of the American Psychological Association and a recipient of its William James award for research in the psychology of religion.