Natan P F Kellermann, PhD was born in Sweden and moved to Israel in 1980. He was a practitioner and trainer of psychodrama and sociodrama and investigated what is helpful in these approaches. He worked in Amcha: an Israeli treatment center for Holocaust survivors and their families for many years. For more than ten years, he lectured on Holocaust trauma at the International School for Holocaust Studies in Yad Vashem. His focus of study is currently the transmission of Holocaust trauma.