Theory of Mind (ToM) entails our imputation of mental states to the self and to others to account for behavior. A foundational question about ToM is whether it is a single unitary construct or differentiates into separable abilities. The predominant accounts of ToM, which are outlined in , most often advocate an integrated view wherein reasoning about the mental states of self and others are deemed to be one and the same cognitive ability.
Predominant accounts of Theory of Mind.
More specifically, the module proposed by the modularity account is said to automatically compute the mental states of self and others. Similarly, according to theory-theory, the conceptual change that occurs during the replacement of successive theories does not distinguish between the mental states of self and others. The sociocultural account assumes that the social contextual variables that drive ToM development equally affect the development of reasoning about self and others' mental states. Finally, the language account does not assess if the relationship between aspects of language differs across self and other reasoning.
Two theories that refute the integrated view in favor of a differentiated view are the Functional Multilinear Socialization
theory. These accounts of ToM distinguish reasoning of one's own and others' mental states as two distinct cognitive abilities that are not purported to emerge necessarily together at a single ontogenetic point in time. The FMS Model poses that ToM capabilities differentiate into the two distinct cognitive abilities of Social Reasoning (reasoning about others'
mental states) and Intrapersonal Reasoning (reasoning about one's own
mental states) [1
]. Moreover, the FMS Model defines Social and Intrapersonal Reasoning in relation to the everyday functions they each play. The Social Reasoning component of ToM is viewed as critically important in social interactions. To carry out successful social interactions, one must be able to understand and predict the mental states of other people, especially when these mental states are inconsistent with reality. The FMS Model is also able to capture a distinct Intrapersonal Reasoning use of ToM-learning. Learning involves the representational change of one's own mental representations. Based on these functional uses, The FMS Model can account for the possibility that children may develop strengths in Social or Intrapersonal ToM.
Simulation theory is the other differentiated account of ToM and proposes that a person initially has a more accurate and advanced reasoning about their own mental states and then uses those advanced self-reasoning skills as a map on which to simulate other's reasoning [3
]. Accordingly, Intrapersonal ToM is always stronger than Social ToM functioning, as simulation theory assigns primacy to reasoning about one's own representations.
Previous research with typically developing populations elucidates that ToM capabilities do in fact differentiate into Social and Intrapersonal constructs. Performance across false belief (which assesses Social ToM) and appearance-reality tasks (which assesses Intrapersonal ToM) is not correlated [5
]. Similarly, Moore and colleagues [6
] found performance across false belief and representational change (or “own” belief) not to be correlated. Ruffman and colleagues' [7
] results also support a differentiated ToM model; the majority of their 5-year olds passed an “other” false belief task, but failed a source task (that assessed a child's understanding of the source of their own representations.) Cutting and Dunn [8
] presented participants with eight false belief tasks, one of which was designed to be a “recall your own” false belief. This “own” task was the only task of the eight not correlated with the others.
Moreover, studies designed to specifically test the FMS Model [1
] have supported differentiated ToM. In 2004, Lucariello found that performance across social and intrapersonal tasks was not correlated in a sample of low-income 5-6-year olds. Lucariello et al. [2
] showed that ToM performance differentiated and was better in the social than intrapersonal condition with low- and middle-SES kindergarten students. In addition, Butler and laucariallo [9
] found evidence of uneven development of Social and Intrapersonal ToM in gifted children, who performed better on intrapersonal than social tasks.
Integrated accounts of ToM cannot account for these data. The fact that ToM differentiates on social and intrapersonal tasks provides compelling evidence that ToM is composed of the distinct abilities of Social and Intrapersonal Reasoning. According to simulation theory, Intrapersonal ToM should always be stronger than Social ToM functioning a suggestion that goes against some of the aforementioned data showing some children exhibit a relative strength in Social ToM [2
]. However, the FMS Model [1
] can account for the fact that children may perform differently on social and intrapersonal tasks and show asymmetric development in both directions with some children showing that a strength in Social Reasoning [1
] and others a strength in Intrapersonal Reasoning [9
Admittedly, Wellman et al. [10
] meta analysis suggests that there are no differences between own and other reasoning tasks. However, this analysis was run only on own and other reasoning within a false belief task paradigm. Many other tasks can be used to measure one's own reasoning such as appearance reality, source, and emotion vignette tasks [7
]. It seems possible that own and other reasoning do not differentiate within the constraints of a false belief task, but do so on other assessments (as supported by the more recent aforementioned studies that were not included in the meta-analysis).
It is important to determine the nature of ToM differentiation in children with autism, as much attention has been given to the hypothesis that autism entails a disturbance in ToM. It has been suggested that this disturbance may underlie and account for the wide range of known symptoms associated with the disorder. However, thus far, research has been conducted primarily under the assumption that ToM is an integrated ability. Studies testing false belief, deception, and emotion almost exclusively use measures that only tap the reasoning of others, but then generalize to suggest poor reasoning about self and other.
In the 1980s it was discovered that children with autism fail to understand another
person's false beliefs about the world [12
]. Numerous studies have replicated this finding (see [13
] for a review). However, none of the tasks directly assessed and/or compared the children's reasoning of their own beliefs and beliefs of others. Deception is also relevant to understanding other minds, as it involves trying to make someone else believe that something is true when it is actually false. It has been found repeatedly that children with autism show difficulties producing and understanding deception [14
]. While a lack of deceptive abilities reflects a problem in understanding others' minds, it is not directly related to one's mental processes about oneself. It has been found that children with autism can recognize simple emotions, but have difficulty recognizing and predicting belief based-emotions (specifically, the emotion of surprise) [16
]. Yet, these tests only measured this ability using scenarios in which children with autism had to predict the mental state of a character
as cause of that character's emotion. Again, the currently accepted integrated definition of ToM has caused us to accept that these children have a general inability to understand mental states as a cause, when their ability to determine if their own
beliefs can cause their own emotions has never been tested.
It is important to note the few studies that have assessed the ability of children with autism to understand mental states of self and self compared to others and have not found significant differences between the two. Admittedly, Kazak et al. [18
] asked young people with autism whether they knew or only guessed what was in a box having on some trials seen inside. In a second condition, children were asked if the experimenter knew or only guessed what was in the box. The results showed no superiority in judging own knowledge versus judging other's knowledge. However, as mentioned earlier in regard to the nonautistic population, it certainly seems possible that own and other reasoning do not differentiate within the domain of knowledge/belief, but do so within other domains and/or other tasks that can be used to measure one's own reasoning.
] study also investigated self-reasoning. They used an appearance-reality task in which children with autism were shown a misleading object. While nonautistic subjects were able to correctly answer an appearance question “What does it really look like?” and a reality question “What is it really?”, only a small percentage of children with autism were able to do so. Although at the surface appearance reality tasks are about an object, they tap into a participants own beliefs about the object. The study, therefore, provides some evidence that children with autism have difficulty understanding their own mental states (about an object), but does not offer insight into this weakness relative to the weakness of understanding others' mental states.
One study tested the dissociation between self and other reasoning in the autistic population and their results support a differentiated
ToM. Leekam and perner [20
] used a simplified version of the Zaitchik (1990) “false photograph” task (which is modeled on the standard false belief task except insofar as it tests children's ability to reason about physical photographic misrepresentation) with a group of teenagers with high-functioning autism. One condition tested false belief of others. The second condition tested what they refer to as photographic misrepresentations, but can be considered what we term “intrapersonal,” as it tapped the participants own beliefs.
In both conditions, participants were shown a doll (Judy) wearing a red dress. In the false belief condition, a second doll (Susan) sees Judy in the red dress and then leaves the room. Judy's dress is changed from red to green, and subjects are asked “What color does Susan think that Judy's dress is?” In the false photograph condition, a Polaroid photo is taken of Judy in the red dress. While the photo is developing, her dress is again changed from red to green and participants are asked “In the picture, what color is Judy's dress?” This question aims to tap into what the subject themselves believe. Only 25% of participants with autism were correct on the false-belief question, but almost all of those tested passed the false-photograph question [20
]. Similar results were obtained by Leslie and Thaiss [21
]. Results like this strongly suggest that individuals with autism have a specific inability to reason about the mental states and processes of others. However, they are not generally impaired in their reasoning abilities about self.
Relatively little research specifically tests the ToM abilities of children with Asperger syndrome, let alone their specific Social and Intrapersonal ToM abilities. Often these children are included in ToM studies, but are folded into samples described as children with autism spectrum disorders (e.g., [28
]). This may reflect that many researchers do not think of Asperger syndrome as a distinct disorder, but a variant of autism, and located on the milder end of the autism spectrum [32
]. The few studies that do analyze the ToM abilities of children with autism separately from those with Asperger syndrome have reported inconsistent results. Some suggest deficiencies in ToM abilities are common to both people with autism and Asperger syndrome [36
]. Others indicate that these deficits are less characteristic of Asperger syndrome and suggest that this may be a basis on which the two conditions can be distinguished [37
]. Nonetheless, all of these studies were based on false belief tasks and were therefore unable to illuminate potential differences across Social and Intrapersonal ToM abilities.
It is also important to note that studies indicating differences in ToM abilities across subjects with autism and Asperger syndrome have often been criticized on the grounds that the findings could be attributable to poor subject matching on language abilities. There has been strong evidence for a positive correlation between verbal skills and ToM abilities [39
]. Thus, some argue the apparently better ToM capacity in people with Asperger syndrome may just be a reflection of their higher verbal abilities [40
]. More research is needed to determine if ToM differentiation patterns are different between children with Asperger syndrome and autism. Differences in verbal abilities need to be addressed and Social and Intrapersonal ToM need to be specifically measured.
The goal of the present study was threefold. The first was to determine if ToM differentiates into Social ToM and Intrapersonal ToM in children with autism and Asperger syndrome. It is hypothesized that ToM will differentiate. This hypothesis is based on (1) previous research in typically developing populations showing ToM differentiation and (2) studies with these populations reporting (only) impairments in reasoning about others' mental states. The second goal was to determine if children with autism and Asperger syndrome exhibit more severe deficits in Social ToM than Intrapersonal ToM. It is hypothesized that both children with autism and Asperger syndrome will exhibit more severe deficits in Social ToM than Intrapersonal ToM. This hypothesis is based on the fact that both disorders are characterized by social interaction impairments, but not necessarily learning impairments [42
] and the FMS Model proposes that Social ToM is used in social interactions and Intrapersonal ToM in learning. The third goal was to determine if ToM differentiates differently for children with autism compared to children with Asperger syndrome. It is hypothesized that children with autism will show an even more severe deficit in Social ToM than children with Asperger syndrome, as the severity of the social interaction impairments is greater in autism [42
] and the FMS Model proposes that Social ToM is used in social interactions. There is no clear hypothesis generated regarding the Intrapersonal ToM abilities in children with autism compared to Asperger syndrome, as to date no research has been conducted on the comparative Intrapersonal ToM capabilities of either population. Moreover, the proposed functional use of Intrapersonal ToM (learning) is not necessarily impaired in either disorder [42