Theory of Mind Deficits in Children With Intellectual Disabilities : A Test of Specificity and Uniqueness Hypotheses

This study was designed to determine (a) whether children with intellectual disabilities have a theory of mind deficit relative to younger children of the same verbal mental age and (b) whether theory of mind in children with intellectual disabilities is domain-specific or related to other general cognitive functions. A group of 15 children with intellectual disabilities (mean age= 10;0), 15 children of average intelligence (mean age= 10;0) and 15 children of average intelligence (mean age= 6:0) matched on verbal mental age with the children with intellectual disabilities. The children were given a series of theory of mind tasks. The children with intellectual disabilities were significantly lower on theory of mind performance from the children of average intelligence of the same age, but not from the younger children of average intelligence matched for verbal mental age. This indicates that the children with intellectual disabilities do not exhibit a theory of mind deficit relative to other children of the same verbal mental age. General cognitive functioning accounted for the difference between the groups and was significantly correlated with theory of mind performance in the group with intellectual disabilities. It is concluded that children with intellectual disabilities do not have a deficit in theory of mind relative to younger children of the same verbal mental age, and that theory of mind in children with intellectual disabilities is not domain-specific, but is related to verbal skills and general cognitive functioning.