Theory of Mind

Understanding Belief

Even very young children know that people behave in ways that satisfy their desires: Two-year-olds are quite able to predict that if someone wants a cookie, he or she will go to the jar containing cookies. However, children do not properly understand belief until about 4 years of age. Beliefs generally can be disregarded in everyday interactions because they are normally true. As a result, others' behavior can be predicted fairly accurately by reference to the actual state of the world. This is not always the case, however, particularly when beliefs are false. In this case, it is necessary to refer to the others' mental states.

The classic test of false belief understanding involves the following short scenario, with dolls and props:

Three-year-olds typically say he will look in Location 2: They predict his behavior on the basis of what is really the case. By the time they are 4 or 5 years old, most children realize that Maxi will look in Location 1, where he thinks the chocolate is; they now realize that a person's behavior is based on how the person represents the world.

Another version of the false belief task is the unexpected contents task. Here, a child is shown (for example) a Smarties container and is asked “What's in here?” After answering “Smarties!” the child is shown that it contains only a pencil. The container is closed again, and the child is asked, “What did you think was in here before I took the top off?” Three-year-olds typically answer “a pencil,” despite having just had a false belief to the contrary. They also predict that their friend, who has not seen inside yet, will think there is a pencil inside. This suggests that people may not have special insight into their own mental states; at least for outdated beliefs, people reconstruct them in a theory-like process, as they do when predicting others' mental states.

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