Attachment theory is a model of psychological development formulated primarily by John Bowlby and expanded by Marie Ainsworth that recognizes and analyzes the relationship between an infant and their primary caregiver. Central to attachment theory is the idea that the bonds that are or are not formed in early childhood are responsible for the subsequent emotional reactions of the adult. Bowlby also identified multigenerational patterns of attachment. Ainsworth built on Bowlby’s approach, identifying various modes of non-attachment by studying individual emotional attachment styles in one- to two-year-olds. Her work is considered seminal in the case for attachment theory, which gained prominence in the field of psychoanalysis in the 1950s and 1970s.

Another contributor to the theory of infant development is developmental psychologist Erik Erikson. Erikson formulated eight psychological stages of infant development, each of which contains a conflict, a corresponding event, and a desired emotional outcome. This model is vital to Maté’s work, which likewise conceives of infant development as passing through stages that may or may not resolve successfully.

In Scattered Minds, the psychosocial model of attachment theory becomes biopsychosocial as Maté uses attachment theory as a lens through which to understand the physiological signs of ADD. Maté examines the emotional triggers responsible for neurochemical production in the brain, especially during infancy—the period most responsible for the formation of the cortex.