Theory of mind abilities in young siblings of children with autism.

Deficits in theory of mind (ToM), evident in most individuals with autism, have been suggested as a core deficit of autism. ToM difficulties in young siblings of children with autism (SIBS-A) compared to siblings of typically developing children (SIBS-TD) would place the former within the broad phenotype. We examined ToM's possible associations with measures of language, cognition, and daily living skills. Participants comprised 24 SIBS-A and 24 matched SIBSTD aged 4.6 years. They completed the false belief and the strange stories tasks. We also collected measures of verbal and cognitive ability and daily living skills. Non-significant differences emerged between the groups on both ToM tasks. Differences did emerge in within-group associations between ToM ability and receptive language. The conclusion is that SIBS-A show resilience in ToM abilities. Possibly, these deficits are not genetically transferred to siblings, at least as measured in laboratory-based ToM tasks.