Deafness, conversation and theory of mind.

The child's developing theory of the mind as an interconnected network of beliefs, desires and feelings that govern behaviour provides a cornerstone for social and intellectual life. Recent research has suggested that autistic children have difficulty acquiring such a theory. Although it is speculated that a specific neurological deficit may be responsible for autistic children's difficulties on false belief tasks devised to test a theory of mind, these may also be due to a lack of exposure to conversation about mental states. In this study we explored the development of a theory of mind in a group of 26 signing, prelingually-deaf Australian children of normal intelligence, aged 8-13 years. Results revealed that 65% of these deaf children failed a simple test of false belief which normal preschoolers, mentally retarded children, and other handicapped groups--apart from children with autism--routinely pass at a mental age of 4-5 years. No significant difference emerged between deaf children's performance and that of autistic children tested on the same task in previous research. We discuss the results in terms of a conversational account of the development of a theory of mind in deaf children, and the extent to which this account is applicable to children with autism.