Aspects of a Theory of Mind and Self-Reports of Quality of Life by Persons with Mental Retardation

The present study examined the assumption that individual differences on aspects of the cognitive development of a Theory of Mind (TOM) may account for differences in the capacity of persons who are mentally retarded (MR) to provide accurate, reliable, and valid self-reports of their quality of life (QOL). Seventy-five adults with mild to moderate levels of mental retardation and basic communication skills filled out a multifaceted measure of QOL which included a measure of acquiescence. In addition, they were asked to perform four TOM tasks, two related to the ability to attribute ignorance and two related to the ability to attribute false belief. As expected, TOM development was found to be negatively related to acquiescence. However, no relation was found between TOM development and the reliabilities of self-reported QOL. In addition, relations between TOM and these self-reports were in the opposite direction to what was predicted on the basis of the assumed association between the validity of the self-reports and TOM development. The self-reported QOL of persons with less developed TOM tended to differentiate between different degrees of inclusion, whereas those of persons with more developed TOM did not. Furthermore, TOM was shown to be positively related to self-reported QOL.