A Theory Built in a Nursery

John Bowlby's claim was evolutionary before it was clinical. Human infants are helpless for an extraordinarily long time, so there must be a behavioural system that keeps a caregiver close, and distress at separation is that system working rather than a fault.

Mary Ainsworth built the procedure that let it be observed. The Strange Situation puts an infant through a sequence of brief separations and reunions with a caregiver and a stranger, in an unfamiliar room, and it is the reunions that carry the classification.

That detail is routinely lost and it is the design of the whole thing. Almost every infant is distressed by separation, so distress discriminates nothing. What differs is what happens when the caregiver comes back. A secure infant seeks contact and is comforted and returns to exploring. An avoidant infant does not approach. An anxious or resistant infant seeks contact and cannot be settled by it. A fourth classification, disorganised, was added later for infants whose reunion behaviour is contradictory or frightened in a way the original three could not describe without distortion.

The underlying idea is the secure base. A caregiver whose responses are reliable makes exploration possible, because the child can go out on the assumption that there is something to come back to. A secure base is not a place where nothing happens. It is a place you return to after something has.

In 1987 Cindy Hazan and Phillip Shaver proposed that adult romantic bonds run partly on the same system, with partners functioning as attachment figures for each other. That paper opened an enormous literature and is the reason attachment vocabulary is now everywhere.

It is also the point at which the theory started being overstated, and the overstatement runs in one particular direction.

In its careful form the claim is that early caregiving produces expectations about whether people will be available and responsive, that those expectations are carried forward as defaults, and that defaults are revisable by later experience. Longitudinal studies find continuity from infancy to adulthood that is clearly above chance and a long way below destiny.

In its popular form, attachment styles have become fixed personality types. People describe themselves as an anxious or an avoidant the way they might describe a blood group, and treat it as an explanation of their entire romantic history.

The research does not support that, and says close to the opposite. Styles measured within relationships vary between relationships, and they move over time, particularly in response to a partner who behaves differently from the expectation.

Notice which way the error runs. The deterministic version is more popular than the evidence warrants, and it happens to be the version that removes your responsibility for how you behave. That is worth watching in any theory that becomes popular quickly, and it is not a reason to dismiss attachment theory, which is among the better supported ideas in psychology. It is a reason to hold the careful version rather than the one that arrived on a diagram.