For four decades, a controversial idea has shaped how autism is understood by researchers, healthcare professionals and the public: the claim that autistic people are “mind blind”. The phrase suggests an inability to grasp what others think or feel. It is simple, memorable – and wrong.
The claim rests on a concept called “theory of mind”. In everyday terms, theory of mind is the ability to recognise that other people’s thoughts, beliefs and emotions may differ from your own. This idea explains why someone understands that a joke can fall flat, that a promise can be broken, or that a friend can be mistaken without lying. It is often presented as the key to how people make sense of one another.
The idea entered psychology in the late 1970s, when researchers began asking how children learn to reason about other minds. Simple stories were designed to test this ability, often involving a character who holds a false belief. If a child could predict that the character would act on that belief, they were taken to have a theory of mind. These tasks quickly became a standard tool in developmental research.
In 1985, one such test was used in a study of autistic children. In the “Sally-Anne” task, a doll (Sally) hides a marble, leaves the room, and returns after another doll (Anne) has moved it. Asked where Sally will look, many autistic children in that study gave the “wrong” answer.
