Dr Alan Sroufe has been described as "attachment chief spokesman in the United States"  He conducted a longitual/prospective study of 170 people from birth to middle age looking at the type of attachment they had in infancy and what happened to them in subsequent years. He found certain types of experiences in infancy increased the chances that one might develop an anxiety disorder in adolescents. He is the author of three books: The Development of the Person: The Minnesota Study of Risk and Adaptation From Birth to Adulthood, Emotional Development: The Organization of Emotional Life in the Early Years, and A Compelling Idea: How We Become the Persons We Are and 150 scientific papers.