John Bowlby

Edward John Mostyn Bowlby, born in 1907 into the British upper-middle class, founded attachment theory - the framework that grounded the infant-caregiver bond in evolutionary biology and reshaped developmental psychology.

His father, surgeon to the royal household, was largely absent; his mother followed the era's belief that parental attention spoiled children, seeing her own only an hour a day. Bowlby's primary caregiver was the nanny Minnie, whose departure when he was four he later described as the loss of a mother. Boarding school at seven was a deeper scar.

At Cambridge he turned from medicine to developmental psychology, qualifying as a physician in 1933 and training as a psychoanalyst under Melanie Klein. He broke with Klein on a basic question: she stressed the child's fantasies about the mother; he insisted on the actual history. His 1944 paper Forty-Four Juvenile Thieves showed that 17 of 44 delinquent boys had endured prolonged maternal separation before age five - an empirical seed of attachment theory.

After the war Bowlby became deputy director of the Tavistock Clinic and, from 1950, WHO mental-health consultant. The 1951 report Maternal Care and Mental Health argued that the developing child needed a warm, continuous relationship with a primary caregiver. It triggered worldwide reforms and abolished hospital visiting restrictions, but was also weaponized to discourage mothers from working. A 1962 follow-up with Mary Ainsworth clarified that any consistent, responsive caregiver could serve the role.

From the late 1950s Bowlby integrated ethology - Lorenz's imprinting, Tinbergen's instinct studies - to recast attachment as an evolved survival strategy. The Attachment and Loss trilogy (1969, 1972, 1980) and A Secure Base (1988) developed the model: secure relationships build internal working models that organize affect and behaviour across the lifespan. With Ainsworth's Strange Situation supplying evidence, the theory became dominant in the field.