Bruce J. Ellis, Ph.D., is Professor of Family Studies and Human Development and the John & Doris Norton Endowed Chair in Fathers, Parenting, and Families at the University of Arizona. Dr. Ellis was originally trained as a canonical evolutionary psychologist in David Buss’ laboratory at the University of Michigan, where he studied adult sexual and romantic relationships. Developmental processes were largely taken for granted in this context. Dr. Ellis became dissatisfied with this approach, undertook three years of postdoctoral training in developmental psychopathology at Vanderbilt University, and shifted from studying adult behavior to developmental processes and mechanisms. His theoretical writings and empirical work seek to integrate evolutionary and developmental perspectives on the role of family environments in regulating child stress reactivity, pubertal development, and adolescent sexual behavior. He is particularly interested in mapping key dimensions of the environment that children’s brains detect and respond to, how these dimensions become embedded in the physiological parameters—set points and reactivity patterns—of stress response systems, and the role of different stress response profiles in mediating and moderating the development of life history strategies (e.g., timing sexual maturation, intrasexual competitive behaviors and risk-taking, patterns of mating and parenting). Dr. Ellis’ work has been recognized by major awards from the American Psychological Association, the Human Behavior and Evolution Society, and the John F. Kennedy Center for Research on Human Development. Dr. Ellis leads the Frances McClelland Institute initiative on Fathers, Parenting, and Families at the University of Arizona.