Attachment and Health
John Bowlby and Mary Ainsworth developed attachment theory in the 1960s while investigating the effects of maternal separation on infant development. The development of the Strange Situation task in 1965 by Ainsworth and Wittig allowed researchers to systematically investigate the attachment system operating between children and their parents. The Strange Situation involves separating infant-parent dyads and observing infant behaviours upon reunion. Infant behaviour tended to follow patterns, leading to the development of three attachment categories: Secure, Anxious-Avoidant, and Anxious-Resistant. In 1990, Ainsworth added a new category, championed by Mary Main, called Disorganized/Disoriented attachment, characterized by its less reliable pattern of behaviour.
Attachment theory
Beginning in 1970, a series of expansions were added to Ainsworth's original patterns. They include the following: B4 (1970), A/C (1985) D/disorganized (1986), B5 (1988, 1992) A+, C+, & Depressed (1992, 2010). At later ages, additional categories have been described. Each of these patterns reflects a different kind of attachment relationship of the infant with the mother/caregiver. An infant may have a different pattern of attachment to each parent as well as to alternate caregivers. Pattern of attachment is thus not a part of the infant, but is characteristic of the protective and comforting quality of a specific relationship. These attachment patterns are associated with behavioral patterns and can help further predict a child's future personality.