Ariel Knafo-Noam is professor of developmental psychology at the Psychology Department, The Hebrew University of Jerusalem. He holds a PhD in psychology from The Hebrew University, and had postdoctoral training in educational psychology at the Ben Gurion University of the Negev, Israel, and in behavior genetics at the Social, Genetic, and Developmental Psychiatry Research Centre, King’s College London. He is interested in the genetic, environmental and combined contributions to development of altruism, empathy and other aspects of prosociality. Using longitudinal developmental studies, he investigates parent-child as well as child-parent genetic-environmental reciprocal or circular influences. He has been studying the development of empathy as a dispositional trait, with several longitudinal and genetically-informative studies.