Theory of mind is the ability to understand that another person can have knowledge, emotion beliefs and intentions that are different to our own. One of the ways ToM is investigated is using the Sally-Anne task. In the Sally-Anne task, there are two dolls: Sally (who has a basket) and Anne (who has a box). Sally puts her marble in her basket and leaves the room. After Sally has left the room, Anne takes the marble from the basket, and hides it in her box. Sally then returns to the room and the child is asked three questions:
- Where will Sally look for her marble?
- Where is the marble really?
- Where was the marble at the beginning?
These three questions are testing the child’s memory, whether they understand the reality of the situation and whether they understand what sally’s belief will be.
Children who have ToM will understand that Sally will look in her basket, as this is where she left it. Children who have not developed a ToM will say that Sally will look in Anne’s box, as they mistakenly assume Sally has the same knowledge they do.
Similarly to children who have not developed a ToM, children with autism struggle to pass this task, even though there are no issues with intelligence.