Over the past more than 20 years, I have worked in close collaboration with my colleague at Western, David Pederson. Throughout that time, we have pursued a better understanding of the nature, origins, and consequences of the first human relationship between an infant and her mother. This work has taken us into a variety of domains, including the description of naturalistic patterns of early interaction, an examination of the mother’s state of mind regarding intimate relationships, the impact of childhood sexual and physical abuse on the attachment relationship, and the special challenges faced by adolescent mothers and their infants.