Autism Spectrum Disorder was first identified in the mid-twentieth century by physicians Leo Kanner and Hans Asperger. Symptoms associated with the condition are “present from early childhood and limit or impair daily functioning” and “disturbances are not better explained by intellectual ability” (American Psychiatric Association, 2013).
Since its discovery, there have been numerous advances in the diagnosis of autism, with several symptoms being outlined in DSM-IV and DSM-V. The Triad of Impairment (Wing & Gould, 1979), for instance, describes difficulties in interaction, communication and imagination (American Psychiatric Association, 1994), while a more recent characterisation stipulates impairments in social communication and interaction, and restricted or repetitive behaviour, interests and activities (American Psychiatric Association, 2013).
One of the most researched theories pertaining to autism is the Theory of Mind hypothesis. It was introduced three decades ago by Premack and Woodruff (1978) with their work on primatology, and presents the idea that autistic people do not have the ability to “attribute mental states to themselves and others” (Baron-Cohen et al. 1985).
“A theory of mind remains one of the quintessential abilities that makes us human (Whiten, 1993). Having a theory of mind is to be able to reflect on the contents of one’s own and other’s minds. Difficulty in understanding other minds is a core cognitive feature of autism spectrum conditions. The theory of mind difficulties seem to be universal among such individuals.” (Baron-Cohen 2001, 3).
When published, it was believed that the Theory of Mind hypothesis provided an explanation for the symptoms related to autism, for instance, a lower frequency of spontaneous pretend play (Wing et al., 1977; Baron-Cohen, 1986), and difficulties with inferring other people’s emotions and intentions, and with understanding metaphor, sarcasm and irony (Baron-Cohen, 1997).
In recent years, however, this theory has been criticised as it has been discovered that the lack of this ability is not universal (Dahlgren & Trillingsgaard, 1996) nor exclusive to autism (Pellicano, Maybery, Durkin & Maley, 2006), with studies showing that only 80% of autistic people lack a theory of mind (Tager-Flusberg, 2007). Additionally, since its publication, many other theories for the causes of autism have been put forward and it is argued that these better rationalise the symptomatology. This essay will explore how successful recent research has been in explaining the symptoms of autism.
The Theory of Mind hypothesis attempts to posit an explanation for autistic individual’s impairments in social communication and interaction. Numerous attempts have been made to explain symptoms such as, difficulties with reading facial expressions, with tuning into the achievements of others, with emotional signals, with understanding people’s feelings, and with comprehending humour and innuendo, among others (The National Centre for Learning Disabilities, 2013).
Intention is an early marker of theory of mind development. Children with autism seem to be lacking in common sense when they interpret other people’s requests, as they may interpret speech too literally (Robinson and Mitchell, 1992). This may be because they lack the understanding of the other person’s intentions. Theory of Mind is, also, associated with poor social interaction, because the lack of an ability to interpret another person’s mental state leads to misunderstandings.
The methodology used to evaluate whether an individual has developed a theory of mind is called a false belief task (Dennett, 1978). A distinction is made between different stages of theory of mind functioning (Baron-Cohen, 2000). In first-order false belief tasks, one must deduce others’ beliefs with regards to real events, whereas second-order false belief tasks require attributions about others’ false beliefs based on someone else’s thoughts (Perner & Wimmer, 1985). These tasks correspond to a mental age of between 4 and 8. At this age, children begin to understand that an individual can believe something that is wrong and that in this case, they must attribute a false belief to said person (Astington, 1993; Wellman and Bartsch, 1988).
Although false belief tasks come in many forms, the most famous is Baron-Cohen, Leslie & Frith’s Sally-Anne Task (1985), where the individual must discern where Sally thinks her marble is, after Anne has changed its location. By answering correctly, the individual shows that he/she recognises that a person can have a different viewpoint (mental state) to their own.
Other tests include the Strange Stories Test (Happé, 1994), which involves reading stories which contain forms of deception, double bluffs and white lies; the Faux Pas Test (Stone et al., 1998) where children must recognise whether a faux pas was made and why, e.g. someone said something awkward or inappropriate, and what the intentions and beliefs of this person are; and the Reading the Mind in the Eyes (Baron-Cohen, Jolliffe, Mortimore and Robertson, 1997), where individuals must interpret the emotional state of a person solely based on a picture of their eyes. All these tests measure, to some extent, the individual’s social sensitivity.
However, it has been found that the level of difficulty with regards to Theory of Mind depends, to some degree, on language ability and Intelligence Quotient (Baron-Cohen et al. 2000). Also, some research has shown that children with autism can show a drastic change in theory of mind abilities over time (Steele, Joseph & Tager-Flusberg, 2003) and that this ability can be improved via training in social skills (Ozonoff & Miller, 1995). This suggests that people with autism who have learned to ascribe mental states due to early social interaction, for instance, ‘maternal mind-mindedness’ or by breaking down social behaviour (Meins, Ferneyhough, Wainwright, Das Gupta, Fradley & Tuckey, 2002), would not fit this category. The latter point is argued, however, in that, even with training, this skill would not be intuitive or preeminent.
Additionally, repeats of the original Reading the Mind in the Eyes test have shown no impairment for the autistic individuals who took part. This supports the hypothesis put forward by Roeyers et al., in 2001, that this test may not be a valid measure of the presence of theory of mind. However, the Strange Stories test, which has yielded results in favour of the theory of mind hypothesis, is considered a more valuable instrument because it more closely resembles a real-life situation, so it is speculated that this could be why the Reading the Mind in the Eyes test has contradictory results.
Further, it has been speculated that failures in this test are based on a verbal interpretation (Bloom & German, 2000), so would not be apt for non-verbal children or for those who find difficulty in understanding language. It became clear, from these tests, that the misunderstanding of the language would affect the pragmatic comprehension required to pass the test. For this reason, another test was developed that doesn’t take verbal abilities into account.
The Executive Function is an umbrella term for a “range of higher order functions, explicitly linked to the prefrontal cortex, which help guide flexible, goal-oriented behaviour.” (Lezak, 1995; Luria, 1966; Pennington and Ozonoff, 1996; Russell, 1997). They are required when having to pay attention or concentrate (Burgess & Simons 2005, Espy 2004, Miller & Cohen 2001).
These functions include planning, organising, switching focus and impulse control (Boucher, 2009; Cumine et al. 2009). Research has established three core executive functions: inhibition, working memory and cognitive flexibility (Lehto et al. 2003, Miyake et al. 2000). The Executive Dysfunction Theory attempts to give an explanation for the second set of symptoms established in the DSM-V: restricted or repetitive behaviour, interests and activities.
Tests for a deficit in executive functions include the Stroop task (Stroop, 1935), the Wisconsin card sorting test (Grant & Berg, 2000), and the Trail-making test (…, 1944). The first requires the subject to recite the colours of words of colours; the second to work out how to classify cards when without being told the criteria, only whether the card is classified correctly or not; and the third to connect a set of dots at quickly as possible. These tasks test for inhibition, task switching and visual attention, respectively.
Further research, however, has shown that autistic people can do well at problem-solving tasks that do not require verbal processing (Dawson et al. 2007) and there is some evidence that individuals diagnosed with ASD have performed well on executive function tasks.
The Central Coherence Theory was presented as an alternative because neither the Theory of Mind Hypothesis nor the Executive Dysfunction Theory could explain “superior areas of skill” (Frith, 1989). This is because despite a large amount of people with autism being classed under the term ‘mentally retarded’ (e.g. Asarnow, Tanguay, Bott, & Freeman, 1987; Burack, 1992, 1994; Burack & Volkmar, 1992; DeMyer, 1979; Gillberg, 1993; Myers, 1989; Prior & Werry, 1986; Rutter, 1974; Rutter, Bartak, & Newman, 1971; Seligman, Walker, & Rosenhan, 2001; Volkmar & Cohen, 1988; Wing, 1974, 1976), the original prognosis described them as having “excellent memory…and the precise recollection of complex pattern and sequences, bespeak good intelligence” (Kanner, 1943).
Autism may, in part, be characterised by a “weak drive for central coherence” (Frith, 1989; Frith & Happé, 1994). This means that individuals with autism may not process information at the normal global level, but rather, in a local, specific way, thus seeing details better than they do the big picture. Therefore, a way of testing for a weak central coherence would be to see if individuals excel at tasks that require a more analytic approach, where a global methodology would otherwise omit information.
Tasks used to test one’s central coherence involve embedded figures (Happé, 1994), and research by Shah and Frith (1983) revealed that children with autism performed better than controls at these tasks (Witkin, Oltman, Raskin & Karp, 1971). The Navon Task, is described as an alphabetised Stroop test, where subjects must read out small letters that make up larger ones. Research shows that not only were autistic children more efficient at reading out the smaller letters, but they made more mistakes when having to read at a global level, whilst the opposite was true for typically developing children (Navon, 1977). Another task, the Block Design Test involves rearranging a group of blocks to match a pattern displayed in front of them. This task employs motor and visuo-spatial skills, and requires the subject to focus on the distinct parts of the design. Once again, individuals with ASD were faster and more efficient at completing this task than those without ASD.
Further, Shah and Frith (1993), found that this superiority in children with autism was reduced once the figure to be reproduced was partitioned. This is to say that as soon as the characteristic of the object became the complete object, this ability was lost, which attests to this theory. This theory would explain autistic individual’s preoccupation with parts of objects and their ability to detect minor environmental changes.
On the other hand, it has been shown that individuals with autism are still able to process information globally when they are instructed to do so (López et al. 2004, Plaisted et al. 1999, Snowling and Frith, 1986). For this reason, and because the Theory of Mind hypothesis does not take into account the non-social aspects of autism, another theory: the Empathising-Systemising Theory was put forward (Baron-Cohen, 2008).
The E-S Theory was established as a reconceptualisation of cognitive differences between sexes, wherein it is believed that the male brain is significantly better at systemising than empathising and the female is the opposite. Based on this, it is conjectured that autistic individuals can be contemplated as having this male brain profile. Baron-Cohen (2008) speculated that this difference in ability was due to the quantity of prenatal testosterone, where a larger amount would lead to a higher systemising capacity and a lower empathising ability, and vice versa. Individuals who systemise look for rules so they can possess a better control of their environment
Two tests have been devised to assess the magnitude of social impairment in people with autism: the Empathy Quotient Test (Baron-Cohen and Wheelwright, 2004) and the Systemising Quotient Test (Baron-Cohen, Richler, Bisarya, Gurunathan, and Wheelwright, 2003). Together, these constitute a 120-item questionnaire, with a scale of four possible answers, ranging from highly agree to highly disagree.
The strength of this theory is that it explains both the social and non-social aspects of autism, by clarifying the deficits in empathy (understanding mental states and responding to them) and above average systemising abilities (repetitive behaviour, dislike of change and obsessive interests) associated with ASD. However, due to its focus on the differentiation between genders, it has proven to be controversial. Many have criticised the theory, not solely because of the gender stereotypes it perpetuates, but due to research into empathising and systemising in children’s early life, which shows that there are no clear differences between how boys and girls develop (Nash & Grossi, 2007).
There appears to be substantial evidence that the Theory of Mind hypothesis explains some of the symptoms of autism, as it has been shown that, as a whole, children with autism are hindered with respect to their procurement of a theory of mind, compared to typically developing children. For instance, what children with autism achieve with a verbal age of up to 13 years, typically developing children can do by the age of 4 (Fisher, Happé and Dunn, 2005; Happé, 1995). However, some inconsistencies in the research, with different researchers finding differing results (e.g. Kaland et al. 2002; Stone et al. 1998; Zalla et al. 2008; and Ponnet et al 2004; Roeyers et al. 2001), and the inability of the theory to explain all the symptoms, have led to a fair amount of criticism.
Some authors have postulated that each of the previously-described theories gives an explanation for one of the core symptoms of Autism Spectrum Disorder. Nevertheless, there is no one theory capable of rationalising the broad scale of autistic symptomatology, as this would have to comprise the cognitive, social and perceptual aspects of the disorder. Despite its wide acceptance, the Theory of Mind hypothesis, as previously stated, does not account for non-social symptoms nor does it give an explanation for symptom severity in autism. Until these issues are addressed, this theory cannot be considered as a comprehensive account of autism.
Additionally, Happé, Ronald and Plomin (2006) maintain that no theory will ever be able to fully explain the triad of impairment because all of these symptoms are found in the typically developing population, independently of each other and in less extreme forms. The idea is that, as the triad of symptoms do not associate with each other (Happé et al. 2006), it is impossible to create a theory that will be able to integrate them. For this reason, it is believed that only multi-faceted theories (Baron-Cohen & Swettenham, 1997), that take into account the symptomatology individually, will be able to give an explanation for autism.