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.
Kübler-Ross model
The model was first introduced by Swiss-American psychiatrist Elisabeth Kübler-Ross in her 1969 book "On Death and Dying", and was inspired by her work with terminally ill patients. Motivated by the lack of instruction in medical schools on the subject of death and dying, Kübler-Ross examined death and those faced with it at the University of Chicago medical school. Kübler-Ross' project evolved into a series of seminars which, along with patient interviews and previous research, became the foundation for her book. Although Kübler-Ross is commonly credited with creating stage models, earlier bereavement theorists and clinicians such as Erich Lindemann, Collin Murray Parkes, and John Bowlby used similar models of stages of phases as early as the 1940s.