Developmental psychology
Attachment theory, originally developed by John Bowlby, focuses on the importance of open, intimate, emotionally meaningful relationships. Attachment is described as a biological system or powerful survival impulse that evolved to ensure the survival of the infant. A child who is threatened or stressed will move toward caregivers who create a sense of physical, emotional and psychological safety for the individual. Attachment feeds on body contact and familiarity. Later Mary Ainsworth developed the Strange Situation protocol and the concept of the secure base.
Internal working model of attachment
The most influential figure for the idea of the internal working model of attachment is Bowlby, who laid the groundwork for the concept in the 1960’s. He was inspired by both psychoanalysis, especially object relations theory, and more recent research into ethology, evolution and information-processing.