Attachment and Health
John Bowlby and Mary Ainsworth developed attachment theory in the 1960s while investigating the effects of maternal separation on infant development. The development of the Strange Situation task in 1965 by Ainsworth and Wittig allowed researchers to systematically investigate the attachment system operating between children and their parents. The Strange Situation involves separating infant-parent dyads and observing infant behaviours upon reunion. Infant behaviour tended to follow patterns, leading to the development of three attachment categories: Secure, Anxious-Avoidant, and Anxious-Resistant. In 1990, Ainsworth added a new category, championed by Mary Main, called Disorganized/Disoriented attachment, characterized by its less reliable pattern of behaviour.
Active perception
Active Perception is part of the broader field of ecological psychology. Ecological Psychology (and theories of Ecological Perception) was formulated by gestalt psychologists in the 1930s, and refined by Gibson through the 1950s to 1970s. The theory has held strong, although for the approximately 80 years that it has been around, it has always been considered a niche area of psychology. Ecological Perception has had little traction in medicine, for instance, until recently, when a series of coherent hypotheses proposed that active perception is the basis for developmental disorders and psychiatric symptoms.