As adults, we take it for granted that we know what others are thinking may be different to our own view. Not everyone likes the same things, or has the same beliefs. However, knowing that others have their own interpretations of the world is a skill which is acquired during childhood, and is known as Theory of Mind.
One of the methods used to test at what age children develop this skill are false belief tasks, e.g. the Maxi task (Wimmer & Perner, 1983). In this task, infants see a puppet, Maxi, put a chocolate in a green draw. Maxi leaves, and his mum moves the chocolate to a blue draw. Infants are then asked ‘Where will Maxi look for the chocolate?’ To check any mistakes are not caused by a memory error, they are also asked if they remember where Maxi put the chocolate at the beginning. There is a 50/50 chance of infants getting the right answer, however this study found that only children over the age of 5 performed above chance level – in other words, had developed a Theory of Mind. 80% of children who answered the false belief question wrong got the memory question right showing that their mistake was not due to forgetfulness.
However, this task has been criticised for being too complicated for young children to understand. The question ‘Where will Maxi look for the chocolate?’ could also be misleading, as it could be interpreted as ‘where will he look for (and find) the chocolate?’ Therefore, Seigal & Beattie (1991) repeated this task, but asked children either ‘Where will Maxi look?’ or ‘Where will Maxi look first?’ They found that only 35% of 3-4 year olds answered correctly when asked the original question, and this rose to 71% for the new manipulation. However, as 29% still did not answer correctly, it shows the question does not explain all of the poor performance.
Another method used to measure Theory of Mind are deception tasks. To deceive someone shows that you understand they can hold a different belief to your own. Chandler et al (1989) tested this with young children, who were shown a video of a doll with dirty shoes hiding a treasure in a container, leaving a trail of footprints. The child had to think of a way of deceiving someone who did not see this, so that they would not know where the treasure was hidden. Interestingly, they found that younger children (aged around 2 ½) were better than slightly older children (around 3 ½) at choosing deceiving strategies such as wiping out the genuine trail or laying a false one. However, from 4 years of age, performance increases.
These studies suggest that Theory of Mind is acquired at around the age of 4-5. However, there is still some debate about whether this ability is caused by gradual development, or a sudden shift. It is now thought more likely that this is skill is gradually learnt, as older children can fail to show complete Theory of Mind, without passing false belief tasks.
There is also evidence that Theory of Mind is not fully acquired in children with autism until they are much older. Baron-Cohen et al (1985) carried out a false belief tasks with children with autism, and healthy controls. They found that at the same age, 80% of the autistic children failed, whereas 87% of controls passed. While deficits in Theory of Mind cannot account for all of the symptoms of autism, and not all autistic children fail false belief tasks (20% passed in the Baron-Cohen study), problems with this skill could be a result of other cognitive deficits, such as planning, inhibition, and belief flexibility.
I’ll stop here before this blog post turns into 1000’s of words long, but please check back soon for my next post on autism in childhood.