Prior research demonstrates that understanding theory of mind (ToM) is seriously and similarly delayed in late-signing deaf children and children with autism. Are these children simply delayed in timing relative to typical children, or do they demonstrate different patterns of development? The current research addressed this question by testing 145 children (ranging from 3 to 13 years) with deafness, autism, or typical development using a ToM scale. Results indicate that all groups followed the same sequence of steps, up to a point, but that children with autism showed an importantly different sequence of understandings (in the later steps of the progression) relative to all other groups.

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.

Children aged 3 to 12 years (n=184) with typical development, deafness, autism or Asperger Syndrome took a series of theory-of-mind (ToM) tasks to confirm and extend previous developmental scaling evidence. A new sarcasm task, in the format of Wellman and Liu’s (2004) 5-step ToM scale, added a statistically reliable sixth step to the scale for all diagnostic groups. A key previous finding, divergence in task sequencing for children with autism, was confirmed. Comparisons among diagnostic groups, controlling age and language ability, showed that typical developers mastered the six ToM steps ahead of each of the three disabled groups, with implications for ToM theories. The final (sarcasm) task challenged even nondisabled 9-year-olds, demonstrating the new scale’s sensitivity to post-preschool ToM growth.

To examine cultural contrasts in the ordered sequence of conceptual developments leading to theory of mind (ToM), we compared 135 3- to 6-year-olds (77 Australians; 58 Iranians) on an established 5-step ToM scale (Wellman & Liu, 2004). There was a cross-cultural difference in the sequencing of ToM steps but not in overall rates of ToM mastery. In line with our predictions, the children from Iran conformed to a distinctive sequence previously observed only in children in China. In contrast to the case with children from Australia (and the United States), knowledge access was understood earlier than opinion diversity in children from Iran, consistent with this collectivist culture's emphasis on filial respect, dispute avoidance, and acquiring knowledge. Having a sibling was linked with faster overall ToM progress in Australia only and was not related to scale sequences in either culture.

It has been argued that children who possess an advanced theory of mind (ToM) are viewed positively by their peers, but the empirical findings are mixed. This meta-analysis of 20 studies including 2,096 children (aged from 2 years, 8 months to 10 years) revealed a significant overall association (r = .19) indicating that children with higher ToM scores were also more popular in their peer group. The effect did not vary with age. The effect was weaker for boys (r = .12) compared to girls (r = .30). ToM was more strongly associated with popularity (r = .23) than with rejection (r = .13). These findings confirm that ToM development has significant implications for children's peer relationships.

Consecutive re-testings of 92 U.S. preschoolers (n = 30), Chinese preschoolers (n = 31), and deaf children (n = 31) examined whether the sequences of development apparent in cross-sectional results with a theory-of-mind scale also appeared in longitudinal assessment. Longitudinal data confirmed that theory-of-mind progressions apparent in cross-sectional scaling data also characterized longitudinal sequences of understanding for individual children. The match between cross-sectional and longitudinal sequences appeared for children who exhibit different progressions across cultures (U.S. vs. China) and for children with substantial delays (deaf children of hearing parents). Moreover, greater scale distances reflected larger longitudinal age differences.Adults consistently interpret each other's actions in terms of underlying mental states (beliefs, desires, and emotions)-termed a theory of mind--and children come to do so in the preschool years (Harris 2006;Wellman 2002). Theory of mind encompasses understanding of various mental states as well as how action is shaped by such mental states and experiences, not only in straightforward situations but also when mind and action are at odds because of forgetting, ignorance, false beliefs, accident, and error. Thus, a "standard" way to assess theory of mind development is through false belief tasks that require inferences about the action or thinking of someone whose beliefs conflict with reality and with the child's own current knowledge. Indeed, theory of mind is sometimes described as a preschool achievement equated with successful performance on false belief tasks. However, we advocate a broader construal, both conceptually and developmentally. Achieving a theory of mind includes understanding multiple concepts acquired in developmental progression (Wellman & Liu 2004;Pons, Harris & de Rosnay 2003). For this reason, researchers have recently established a Theory of Mind Scale and used it to examine sequences of theory-ofmind understanding in different groups of children-typically developing children in several countries as well as deaf and autistic children who experience significant theory of mind delays (e.g. Wellman & Liu 2004;Wellman, et al. 2006;Peterson, et al. 2005).In brief, this scale (ToM Scale) provides a cross-sectional ordering of the developmental ease or difficulty of different theory of mind conceptions. A task battery such as this could sample from many mental state constructs and tasks, but this scale encompasses carefully constructed tasks assessing childhood understanding of (1) diverse desires (people can have different desires for the same thing), (2) diverse beliefs (people can have different beliefs about the same situation), (3) knowledge-access (something can be true, but someone might not know that), (4) false belief (something can be true, but someone might believe something different), and (5) hidden emotion (someone can feel one way but display a different emotion). The tasks are devised to be similar in procedures, language, a...

This paper summarizes the results of 11 separate studies of deaf children's performance on standard tests of false belief understanding, the results of which combine to show that deaf children from hearing families are likely to be delayed in acquiring a theory of mind. Indeed, these children generally perform no better than autistic individuals of similar mental age. Conversational and neurological explanations for deficits in mental state understanding are considered in relation to recent evidence from studies of deaf, autistic, and normally developing children with varied levels of access to talk about mental states at home with family members during the preschool years.

The purpose of the study reported here was to examine the degree to which delays or deficits in developing a theory of mind are specific to children with autism or extend to other groups of atypical children with varying conversational experience and awareness. The performance of deaf children from a variety of conversational backgrounds was compared with that of autistic and normal hearing children on a range of tasks requiring representation of others' mental states. Native signers, oral deaf children, and normal hearing children scored similarly, and their performance exceeded that shown by signing deaf children from hearing families and children with autism. The latter two groups did not differ significantly from each other. These results point to an interplay among biology, conversation, and culture in the development of a theory of mind.