Reactive attachment disorder
The broad theoretical framework for current versions of RAD is attachment theory, based on work conducted from the 1940s to the 1980s by John Bowlby, Mary Ainsworth and René Spitz. Attachment theory is a framework that employs psychological, ethological and evolutionary concepts to explain social behaviors typical of young children. Attachment theory focuses on the tendency of infants or children to "seek proximity" to a "particular attachment figure" (familiar caregiver), in situations of alarm or distress, behavior which appears to have survival value. This is known as a discriminatory or selective attachment. Subsequently, the child begins to use the caregiver as a base of security from which to explore the environment, returning periodically to the familiar person. Attachment is not the same as love and/or affection although they are often associated. Attachment and attachment behaviors tend to develop between the ages of six months and three years. Infants become attached to adults who are sensitive and responsive in social interactions with the infant, and who remain as consistent caregivers for some time. Caregiver responses lead to the development of patterns of attachment, that in turn lead to internal working models which will guide the individual's feelings, thoughts, and expectations in later relationships. For a diagnosis of reactive attachment disorder, the child's history and atypical social behavior must suggest the absence of formation of a discriminatory or selective attachment.
Marinus van IJzendoorn
Van IJzendoorn's main research topic is attachment across the life-span. Attachment has been briefly defined as children's "strong disposition to seek proximity to and contact with a specific figure and to do so in certain situations, notably when they are frightened, tired or ill". Inspired by Darwinian evolutionary theory and Harlow's experimental work with rhesus monkeys, John Bowlby was the first to propose that human genetic selection had favoured attachment behaviours since they increased infant-parent proximity, which in turn enhanced the chances for infant survival. Attachment is considered to be an inborn capacity of every exemplar of the human species. Individual differences in the quality of attachment emerge in the first years of life, and central to attachment theory is the idea that parenting, more specifically parental sensitive responsiveness to the infant's distress signals, determines whether children develop a secure or an insecure attachment relationship with their primary caregiver. Van IJzendoorn introduced in 1995 the quantitative model of the ‘transmission gap’ between parents’ attachments and their infants’ attachment as mediated by parental sensitive responsiveness. This model generated a host of empirical studies trying to bridge the gap (see for a meta-analysis of this work).