Attachment Theory and Research
Authors: Granqvist Pehr , Duschinsky Robbie 
Published: August 2021

Attachment theory was founded by John Bowlby (1907–1990), a British child psychiatrist and psychoanalyst. The theory builds on an integration of evolutionary theory and ethology, cybernetics and cognitive science, as well as psychoanalytic object relations theory. The theory postulates that an attachment behavioral system evolved via natural selection processes. Bowlby conceived of the attachment system as a behavioral control system that continuously monitors the offspring’s proximity to caregivers, which has in turn been associated with protection from dangers and thus increased chances of survival and reproduction in humans’ and many other mammals’ ancestral environments. Attachment is a species-wide phenomenon denoting the strong bonds that children form to their caregiver(s), seeking to maintain proximity and communication, protesting separations, and using the caregiver(s) as a safe haven to return to for comfort and protection and as a secure base to explore the environment from. Attachments take time, maturation, and repeated sequences of interaction to form and are typically observed from the second half of children’s first year of life onward. According to the theory, attachment-related experiences with the caregiver(s) become internalized in the form of cognitive-affective representations of self and others (internal working models [IWMs]) that organize the child’s behavior and displays of affect in relation to the caregiver(s). Although malleable, such IWMs display a certain measure of continuity across time and situations and may generalize to affect the individual’s expectancies and behavioral inclinations in other and later interpersonal relationships. As pioneered by Mary Ainsworth and colleagues, attachments vary in quality, largely depending on the caregiver’s behaviors (e.g., responsivity and sensitivity to the child’s signals), whereas evidence for a direct influence of genetic heritability is limited. Variations in attachment are typically described using two dimensions (secure–insecure, organized–disorganized) subsuming four categories (secure, insecure–avoidant, insecure-resistant–ambivalent, disorganized–disoriented). Much of the empirical research regarding attachment has focused on these variations and their measurement. Ainsworth and colleagues’ Strange Situation Procedure (SSP), applicable for children aged 10–18 months, is often heralded as the “gold standard” attachment measurement tool. The concerted body of research indicates that secure attachment (or associated factors), marked by confidence in the caregiver’s availability, is generally a protective factor in socioemotional development. In contrast, insecure (avoidant and resistant) attachment, characterized by lack of confidence in the caregiver’s availability, is generally a vulnerability factor in development. Disorganized attachment, reflecting confused, conflicted, or apprehensive child behaviors in the presence of the caregiver (in the SSP), is a risk factor in development, most notably for externalizing behavior problems. Notably, the effect sizes observed have typically been small to moderate, and much is unknown about linking mechanisms and moderating influences. Although most readily observed in early childhood, humans form attachments throughout the lifespan. Accordingly, much research has also focused on adult (e.g., spousal) attachment and the intergenerational transmission of attachment from caregivers to their children.