an experimental technique used to assess quality of attachment in infants and young children (up to the age of 2). The procedure subjects the child to increasing amounts of stress induced by a strange setting, the entrance of an unfamiliar person, and two brief separations from the parent. The reaction of the child to each of these situations is used to evaluate the security or insecurity of his or her attachment to the parent. See insecure attachment; secure attachment. [devised in 1978 by Mary D. Salter Ainsworth]