Tuesday, January 11, 2011

false-belief test, again

Another classical study on the theory of mind.

Baron-Cohen et al. (1985) appplied the false belief test to the study of childhood autism. They modified the details of the 'chocolate task' into 'Sally-Anne task' such as;

1.Sally places a marble into her basket.
2.Sally leaves the scene, and Anne transferred the marble and hid it in her box.
3.When Sally returns, the experimenter asks the question: "Where will Sally look for the marble?"
4.If the child points to the Sally's basket, she/he passes the false-belief test.

They compared three types of children: normal preschool children (n=27), children with Down's Syndrome (n=14), and autistic children (n=20).

[T]he results for Down's Syndrome and normal subjects were strikingly similar. 23 out of 27 normal children, and 12 out of 14 Down's Syndrome children passed the Belief Question on both trials (85% and 86% respectively). By contrast, 16 of the 20 autistic children (80%) failed the Belief Question on both trials.
[Baron-Cohen, S., Leslie, A. M., Frith, U. (1985). Does the autistic child have a "theory of mind"?. Cognition 21:37-46, p.42]

And they conclude;

[O]ur results strongly support the hypothesis that autistic children as a group fail to employ a theory of mind. We wish to explain this failure as an inability to represent mental states. As a result of this the autistic subjects are unable to impute beliefs to others and are thus at a grave disadvantage when having to predict the behaviour of other people.
[op.cit., p.43]

[W]e conclude that the failure shown by the autistic children in our experiment constitutes a specific deficit. It cannot be attributed to the general effects of mental retardation, since the more severely retarded Down's Syndrome children performed clos to ceiling on our task.
[op.cit., p.44]

What is relly interesting here, I think, is not that the autistic child lacks the theory of mind but that the Down's Syndrome children performed similarly as the normal children. Down's syndrome children, who are thought to be 'severely retarded', can also pass the fals-belief test.

This fact implies that the theory of mind (or at least, understanding the false belief of others) is not such an intellectual operation as was thought at the beginning. The false-belief test can be answered more intuitively, without theoretical reasoning. So, the question I want to ask here is;

Is the theory of mind truly a theory?

Thursday, January 6, 2011

false-belief test

A talk on the theory of mind (ToM) continues.

Wimmer and Perner (1983) proposed the so-called 'false-belief test', which examines human children's ToM. (The need for testing the 'false-belief' was originally claimed by the philosopher Dan Dennet, as a comment on the 1978 paper by Premach and Woodruff. About their chimpanzee experiments, see the previous post on this blog). The test should have the following formal paradigm.

[T]he subject is aware that he/she and another person observe a certain state of affairs x. Then, in the absense of the other person the subject witnesses an unexpected change in the state of affairs from x to y. The subject now knows that y is the case and also knows the other person still believes that x is the case.
[Wimmer, H. & Perner, J. (1983) Beliefs about Beliefs: Representation and constraining function of wrong beliefs in young children's understanding of deception. Cognition, 13:103-128, p.106]

Based on this paradigm, Wimmer and Perner constructed the well-known 'chocolate task';

[A] story character, Maxi, puts chocolate into a cupboard x. In his absence his mother displaces the chocolate from x into cupboard y. Subjects have to indicate the box where Maxi will look for the chocolate when he returns. Only when they are able to represent Maxi's wrong belief ('Chocolate is in x') apart from what they themselves know to be the case ('Chocolate is in y') will they be able to point correctly to box x. This procedure tests whether subjects have an explicit and definite representation of the other's wrong belief.
[op.cit., p.106.]

The result is enough interesting (and also well-known) that none of the 3 to 4 years old children pointed 'correctly' to the cupboard x. 57% of 4 to 6 years old, and 86% of 6 to 9 years old children pointed 'correctly' to the cupboard x.

They conclude;

[i}t seems, therefore, that the emergence of children's ability to understand another person's beliefs and how this person will react on the basis of these beliefs...seems to emerge within the period of 4 to 6 years.
[op.cit., p.126.]

I agree with their conclusion. The theory of mind is formed in children after (or around) being 4 years. This fact is well examined in many other experiments.

But now, we come to one simple question. If the children under 4 years of age don't have the theory of mind, can't they understand the other person or predict her/his behavior at all? After being 4 years old, they suddenly start to understand the others? If the theory of mind is the only way to understand the others, none of us can understand the others before the birthday party of 4 years old. It sounds so funny, doesn't it?