This article is authored by dept. of Psychology

What is ‘theory of mind’?

X eats half of his chocolate and stashes the rest in the kitchen cupboard. Then he goes outside to have some fun in the sun. In the meantime, his mother enters the kitchen, opens the cupboard, and finds the chocolate. She places it in the refrigerator. Where will X look for his chocolate when he returns to the kitchen? The response to this question would seem to be self-evident. To begin with, X is unaware that his mother has transferred the chocolate. Second, he appears to assume, wrongly, that his chocolate is still in the cabinet. That’s why he’s looking in the cupboard. If you answered the question in this way, you have a ‘theory of mind.’ We instinctively explain people’s actions in terms of their minds: their knowledge, values, and desires, and we know that when belief and reality intersect, it is the person’s belief, not the reality, that defines their behavior. It’s called “having a theory of mind” or “having an intentional stance” to describe actions in this way.

What is the advantage of having a theory of mind?

Through having a theory of mind we can recognize that another person’s knowledge is different from our own. I know what’s behind the rock, but he doesn’t, because, from where he is, he cannot see that there is a scorpion. Having a theory of mind allows us to manipulate other people’s behavior by manipulating their beliefs. If he is my friend I can warn him about the scorpion. If he is my enemy I can tell him it is safe. This latter is called tactical deception or Machiavellianism. Human interactions predominantly involve the dissemination of true or false knowledge for good or for ill.

Who has a theory of mind?

Up to the age of about five years, a child told the story of Maxi and his mother will say confidently that Maxi will look for his chocolate in the fridge. It is as if they assumed that what they know to be true everyone else knows too. Nevertheless, even three-yearolds look first at the cupboard when the question is asked, and even 15-month-olds can be shown to have an inkling of what is going on; their eye gaze pattern shows that they are surprised if Maxi looks in the fridge. But only from age five or so do children show full understanding of the situation and become able to explain exactly why Maxi has a false belief. Children with autism have a specific problem with theory of mind tasks. They expect Maxi to look for his chocolate in the fridge. They reach a mental age of about 10 years before they achieve an understanding of the Maxi task. More complex problems that involve white lies or double bluff take them even longer to learn, and they may never grasp them fully. Theory of mind difficulties can also be acquired through brain damage in frontal cortex or in the region of the temporo-parietal junction. From field studies there are accounts of a range of animals using tactical deception. But there is still argument over whether even chimpanzees show evidence of this in controlled experiments. The current view is that chimpanzees may have a rudimentary theory of mind, but monkeys (and other animals) probably do not.

What is the neural basis of mind reading?

There is currently much interest in identifying a social brain: a circumscribed network of brain regions specialized for the social domain. Mentalizing is one of a number of problems confronting this social brain. When brain activity is measured during the performance of a wide range of tasks engaging theory of mind, two regions have been consistently identified: a medial prefrontal region (paracingulate cortex) and the temporo-parietal junction in the superior temporal sulcus. The medial frontal region is also engaged when subjects reflect upon their own mental states, as well as those of others with the more inferior orbital region responding especially to emotional states. The temporoparietal junction, on the other hand, seems to have a special role in using perceptual cues to recognize the actions and intentions of biological agents. Identification of the precise role of these regions awaits the development of a mechanistic account of our remarkable ability to make inferences about the minds of others.

How is theory of mind possible?

In order to explain people’s behavior on the basis of their minds, we need to have some idea of what is in their minds. The ability to acquire knowledge about other peoples’ beliefs and desires is called ‘mentalizing’ or ‘mind reading’. Our understanding of the mechanisms underlying this ability remains rudimentary. In everyday speech we frequently explain behavior in terms of mental states. Maxi will look in the cupboard because that’s where he believes his chocolate is and because he wants to eat it. Maxi doesn’t know the chocolate is in the fridge. These everyday explanations of behavior in terms of mental states are referred to as folk psychology. Perhaps our ability to mentalize depends upon representations within the brain of the propositions that make up this theory of behavior (referred to as theory theory). On the other hand, perhaps the ability to mentalize is related to our capacity to empathize with other people: to put ourselves into their shoes (this is referred to as simulation theory). An influential view is that mentalizing crucially depends on the ability to form metarepresentations, that is, representations that are decoupled from reality. Thus the truth of the statement, ‘Maxi believes his chocolate is in the cupboard’ does not depend upon where the chocolate is in reality. A possible starting point for developing a mechanistic account of mentalizing comes from the problem of perspective taking. The computation of what another person sees from a different point of view than yours involves translation between egocentric and allocentric spatial coordinates. This translation is also fundamental in spatial navigation. It is perhaps no coincidence that in young children the ability to solve spatial viewpoint problems emerges at about the same age as the ability to solve false belief tasks.