1. Sara R. Jaffee is with the Department of Psychology, University of Pennsylvania, Philadelphia. Antony Ambler, Helen L. Fisher, and Louise Arseneault are with the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, and Neuroscience, King’s College London, London, UK. Melissa Merrick is with the Division of Violence Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, GA. Sidra Goldman-Mellor is with the...