Attachment theory originated in the early 1950s with John Bowlby, a child psychiatrist, and Mary Ainsworth, a psychologist, who both became interested in young children's responses to experiencing loss. They began studying the realms of attachment and bonding. Their theory was developed and integrated over the following 60 years by researchers around the world.
In an effort to understand his observations of psychopathology in young children, John Bowlby developed a theory, strongly influenced by evolutionary concepts, of attachment security as a primary drive. The work of Mary Ainsworth, Beatrice Beebe, and others later demonstrated that the quality of the interaction between the infant and the primary attachment object, usually the mother, predicted the quality of the attachment as well as the ability to deal with novel stimuli and situations in children at ages 12 months to approximately three years. Mary Main, Jude Cassidy, and others, later demonstrated that the mother's report of the nature of her own attachments as a child was strongly correlated with objective ratings of her own child as securely or insecurely attached. During this period, Daniel Stern and others developed detailed models of how infants as young as a few weeks of age begin to develop and retain a representation of the mother-child interactions which they are experiencing. The temperament theorists, notably Jerome Kagan, demonstrated that the infant could bring to the mother-child interaction an influence of its own, and that the very young infant's inherent or genetically given characteristics, reflected largely in its patterns of affective sign and degree of motor activity and autonomic arousal, were factors in later behavior that could be characterized as secure or insecure. Beebe and others showed that the quality of mother-infant "face play" starting at about three months has a profound and durable effect on later measures of security and cognition.