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.
Social connection
Attachment is a deep emotional bond between two people, a "lasting psychological connectedness between human beings." Attachment theory, developed by John Bowlby during the 1950s, is a theory that remains influential in psychology today.