Baron-Cohen, Leslie and Frith (1985)

Does the autistic child have a theory of mind?



The term autism was originally introduced by the psychiatrist Kanner to describe a syndrome (a collection of symptoms) he observed in some of his child patients.

Autistic children typically have difficulties in social interaction and in language and non-verbal communication, and have a restricted range of activities and interests.  Symptoms in all these areas appear before 36 months of age.

Some autistic children have additional cognitive difficulties and many are intellectually impaired.

Some autistic children have exceptional gifts, termed islets of ability, in one particular area, such as music or art.

In most cases autism is a life-long condition, although the patterns of difficulties may change or become less severe as children grow up.

There have been many explanations for the origins of autism and attempts have been made to identify a core deficit which can account for the symptoms of autism.

According to Simon Baron-Cohen the core deficit of autism is the autistic person’s inability to employ a theory of mind. 

It is argued that a child develops a theory of mind between 4 and 6 years of age.  Although some evidence has demonstrated that children as young as two have a theory of mind.  Having a theory of mind is the ability to understand that other people have independent minds of their own.

Developing a theory of mind allows the child to begin to understand other people, and to predict what other people are likely to do and believe.  It is the ability to think about other peoples, or one's own thoughts.

Baron-Cohen argues that autistic people do not seem to develop a theory of mind. 


The aim of Baron-Cohen's experiment was to demonstrate that the central deficit underlying autism is the autistic child's inability to employ a theory of mind.


Three groups of children were used a participants.: 

20 autistic children with a mean chronological age (CA) of 11;11 (11 years, 11 months) and a mean verbal mental age (vMA) of 5;5;

14 Down's syndrome children with a mean CA of 10;11 and a mean vMA 2;11;

27 'normal' children with a CA of 4;5 (who were assumed to have vMA's equivalent to their CA). 

It is very important to note that the mean mental ages of the autistic children (5;5) were higher than the mean mental ages of the Down’s syndrome children (2:11) and ‘normal children’ (4;5).

This experiment is an example of a quasi-experiment (also called a natural experiment) because the three experimental conditions were characterised by the three groups of children who participated.  The independent variable is therefore the type of children used and the dependent variable was whether the child was successful on the Sally-Anne test. 

The 61 children were tested one at a time. 

The children were seated behind a desk opposite the experimenter. 

On the desk were two dolls, Sally and Anne.  Sally had a basket in front of her, and Anne had a box. 

The dolls were introduced to the children (e.g. ‘this is Sally’)

After introducing the dolls, the child's ability to name them was tested (the 'Naming Question'). 

Sally then takes a marble and hides it in her basket.  She then leaves the room and 'goes for a walk'.  Whilst she is away, and therefore unknown to her, Anne takes the marble out of Sally's basket and puts it in her own box.  Sally returns and the child is asked the key question 'Where will Sally look for her marble?'  (the 'Belief Question').  The correct response is to point to or name Sally's basket; that is, to indicate that the child knows that Sally believes the marble to be somewhere where it is not.  The incorrect response is to point to Anne's box.

Two control questions are also asked:  'Where is the marble really?' ('Reality Question'), and 'Where was the marble in the beginning?' ('Memory Question'). 

Every child was tested twice.  During the second time a new location (the experimenters pocket) for the marble was introduced:

For the children to succeed in this task they have to attribute a belief to Sally.  That is, the children have to be able to appreciate that Sally has beliefs about the world which can differ from their own beliefs, and which happen in this case not to be true.     





The percentage of correct responses to each of the four 'Sally-Anne' questions is shown in the table below.


Autistic children

Down's syndrome children

'Normal' children

Naming question




Reality question




Memory question




Belief question





The 'naming', 'reality', and 'memory' questions were answered correctly by all the children. 

However, whereas at least 85% of the 'normal' and Down's syndrome children gave the correct response to the belief question, only 20 % (4 from 20) of the autistic children were able to do so.

The 16 autistic children who gave the wrong response on both trials pointed to where the marble really was rather than to where Sally must believe it to be.


The findings support Baron-Cohen's argument that autistic children have under-developed 'theories of mind'.  According to Baron-Cohen, most of the autistic children were unable to appreciate that another person has their own beliefs which may not match up with how things really are. The results lend support to the notion that autistic children may have under-developed 'theories of mind'.

Evaluation of Procedure

A major strength of the experimental method used by Baron-Cohen was the precise control of variables.  For example, by ensuring that the autistic children were the most intelligent of the three groups he was able to control for levels of intelligence.  He therefore ensured that it was not lower levels of intelligence which caused the autistic children to get the belief question incorrect but rather it was something to do with being autistic.

A major weakness of this method is its lack of ecological validity.  For example, it could be argued that autistic children do not attribute beliefs to dolls because they have a more developed theory of mind than the experimenter who seems to think that a lump of plastic can think in the same way as a person?  The obvious way to improve the experiment would be to use real people instead of dolls as was done by Leslie and Frith (1988).  When this change was made similar results were gained.

Evaluation of Explanation

Baron-Cohen proposed that the core problem in autism is the inability to think about other peoples, or one's own thoughts. 

It is thought that some type of physical damage to the brain causes autism.  This assumes that the development of a theory of mind is a maturational process and therefore an innate capability. 

Baron-Cohen's theory is particularly useful because it seems to provide plausible explanations for many of the symptoms displayed by autistic children.  For example a major difficulty for autistic people is language and non-verbal communication.  If a child lacks the ability to understand another person's thoughts, difficulties in using language for conversation are to be expected.

Autistic children also often have a lack of pretend play. Baron-Cohen argues that this can be explained as an inability to reflect on one's own (rather than another person's) thoughts.  Imagine a child playing at 'mothers and babies' with her doll.  To take the role of mother and treat her doll as the baby, the child must be able to hold simultaneously in her mind two conflicting sets of beliefs.  She knows that in reality she is a little girl, and her doll is a toy.  At the same time she must 'think' the opposite - that she is a mother and her doll is a baby.  So she must 'think about her thoughts'.

However there are problems with Baron-Cohen's theory.  Autistic children have difficulty reflecting on their own thoughts which would seem likely to affect complex skills like solving mathematical problems.  But some autistic children appear to excel at mathematics.

Overall it would seem that Baron-Cohen's theory does go some way in explaining the many difficulties faced by autistic children but that more work still needs to be done.



Baron-Cohen, S., Leslie, A.M., & Frith, U.  (1985) Does the autistic child have a ‘theory of mind’?  Cognition, 21, 37-46




GROSS, R. (1999) Key Studies in Psychology, 3rd Edition. London: Hodder and Stoughton

BANYARD, P. AND GRAYSON, A. (2000) Introducing Psychological Research; Seventy Studies that Shape Psychology, 2nd Edition. London: Macmillan




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And A Bit More Stuff

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Autism is characterised by a triad of impairments.  (i) difficulties with social interaction, (ii) difficulties with verbal and non-verbal communication (iii) a lack of imaginative play.   Autistic children also often display a restricted range of activities and interests and obsessive tendencies.

































Diagram of the Sally Anne test.


And a cute cartoon of Sally and Anne.