Psychology › Development & attachment › Child development and how thinking grows
Theory of mind (the false-belief test)
1983· Finding or experiment
Well replicatedStrong, repeated evidence.
The ability to understand that others have beliefs, wants and knowledge different from one's own, usually firm by about age four.
See it on the Psychology map →What it says
In the classic 1983 test by Heinz Wimmer and Josef Perner, a story character, Maxi, puts chocolate in a cupboard and leaves; his mother moves it. Where will Maxi look? Most three-year-olds point to the new spot, where they know it is; most four- and five-year-olds say the old cupboard, understanding Maxi's false belief. The term 'theory of mind' came from a 1978 chimpanzee study. Children with siblings tend to pass earlier.
Why it matters
It underlies empathy, teaching, persuasion, negotiation and lying. Differences in it help explain some social challenges in autism.
Think of it like
The negotiator's core skill: knowing what the other side believes, including what they believe wrongly.
The evidence
Status: well replicated for the age-four shift. A 2001 meta-analysis of 178 studies by Henry Wellman and colleagues found the same three-to-five transition across countries, varying by a year or so.
Open questions
Whether babies grasp false beliefs much earlier: 2005 looking-time studies suggested 15-month-olds do, but several careful replication attempts have failed.
Connections (4)
▸Theory of mind (the false-belief test) emerges around age four in Child development and how thinking growsWell replicated
The connection
Around age four, most children grasp that other people can hold false beliefs. In the classic test, three-year-olds usually say Maxi will look for his chocolate where it was moved while he was out; five-year-olds say where he left it. This milestone opens the way to keeping secrets, telling white lies and seeing other viewpoints.
Who showed it and when
Heinz Wimmer and Josef Perner, University of Salzburg, Austria, 1983; Simon Baron-Cohen, Alan Leslie and Uta Frith's 'Sally–Anne' version followed in London in 1985.
The evidence
Beyond the 2001 meta-analysis, Wellman and Liu's 2004 scale of five tasks found false belief arrives in a steady order, after children grasp that people can want, think and know different things.
Open questions
Why timing varies: children with siblings, or with parents who often talk about feelings, tend to pass earlier; deaf children of hearing parents often pass later.
▸Theory of mind (the false-belief test) is often delayed in Autism spectrumMixed evidence
The connection
In 1985 Simon Baron-Cohen, Alan Leslie and Uta Frith found most autistic children failed a false-belief test (where will Sally look for her marble?) that most younger typical children passed. They proposed that difficulty imagining others' minds is a core feature of autism.
Who showed it and when
London, 1985 ('Does the autistic child have a theory of mind?'); 80 percent of the autistic children failed, versus about 15 percent of the comparison children.
How solid is it?
Many studies replicate delays on such tests, but many autistic people pass them, especially with age, strong language skills or extra time.
Open questions
The 'double empathy' idea (Damian Milton, 2012) argues understanding breaks down in both directions between autistic and non-autistic people, not just one.
▸Theory of mind (the false-belief test) challenged the timeline of Jean Piaget's stages of cognitive developmentMixed evidence
The connection
Piaget held that children under about seven are 'egocentric', unable to take another person's viewpoint, partly based on his three-mountains task. Theory-of-mind research showed four-year-olds understand others' beliefs, and toddlers grasp others' wants even earlier. With simpler tasks, perspective-taking appears years sooner than Piaget's stages allowed.
Who showed it and when
Piaget and Bärbel Inhelder's three-mountains task, Geneva, 1948; false-belief tests from 1983; Repacholi and Gopnik's 1997 study, where 18-month-olds offered broccoli to an adult who preferred it.
How solid is it?
Many studies show perspective-taking well before seven when tasks are easier; the mountain task demanded spatial skills that masked what children understood.
Open questions
Whether early success reflects real understanding or simpler cues; infant 'implicit' false-belief findings have proved hard to replicate.
▸Social cognition: how we judge people depends on Theory of mind (the false-belief test)Well replicated
The connection
Judging people requires guessing what they think, want and believe, which is theory of mind. Children typically pass false-belief tests around age four, grasping that others can believe something untrue. Adult social judgment, from spotting lies to predicting a negotiator's next move, builds on this ability.
Who showed it and when
Heinz Wimmer and Josef Perner's 1983 false-belief test in Austria; the Sally–Anne test by Simon Baron-Cohen and colleagues in London, 1985.
The evidence
False-belief results replicate widely across cultures; brain imaging links thinking about others' minds to regions such as the temporoparietal junction.
Open questions
Whether infants understand false beliefs much earlier, as some looking-time studies suggest; several of those infant findings have failed to replicate.