Tony Attwood (2006) observed that parents and teachers often send boys for evaluation at the point when their aggressive behaviour becomes a significant problem at home or school. The practice of making referrals based on acting out behaviour, means that overall, more boys will be evaluated, and the perception that aggressive behaviour is significant in AS may mean that parents and teachers overlook children who do not display disruptive behaviour (Attwood, 2006; Wagner, 2006). Girls, for example, may not have tantrums or meltdowns at school, but may instead, refuse to respond to requests or participate in activities (Wilkinson, 2008).
An often present feature in Asperger syndrome is an intense interest in one or more areas (Beteta, 2009), and long, encyclopaedic monologues, often on obscure subjects, are usually recognized as indicating a possible AS diagnosis in boys (Attwood, 2006). Findings suggest, though, that girls tend to have more age-appropriate interests, that generally reflect those of their peers, e.g., horses, or creative pursuits (Attwood, 2006; Beteta, 2009).
Attwood (2006) emphasizes, however, that the dominant role these interests play in the life of a girl with AS is qualitatively different from the role that the same interests play in the lives of her female peers. Attwood (2006) stresses further that a girl’s intense interests can extend well beyond an appropriate age, and that this can help to determine abnormal intensity and focus.
Overall, these observations suggest that increased insight into how these interests function differently for girls with AS, may help to clarify diagnosis.
The use of social echolalia, i.e., mimicking others through imitation and modelling, exists almost exclusively in girls with Asperger syndrome (Beteta, 2009; Wilkinson, 2008). In an effort to reduce their social and communication impairments, girls may copy the mannerisms, voice, persona, and behaviour of others, often quite successfully (Attwood, 2006).
However, Beteta (2009) points out that although girls may seem to benefit from the use of social echolalia, often they do not truly understand the contextual meanings of what they are mimicking.
Ryden and Bejolet (2008) found that adult females also seemed more successful at mimicking social behaviour than adult males, and for this reason, they rarely fit the original description of Asperger syndrome.
This suggests that the use of social echolalia may hinder the recognition and diagnosis of AS, and consequently, access to relevant support (Attwood, 2006), and that girls and women may experience increased stress in dealing with the consequences of mimicking behaviours that they may not quite understand.
Overall, a greater awareness of gender differences in phenotypic expression is vital so that girls will receive an accurate diagnosis, and access to services that could lessen the impact of AS, particularly beyond childhood.
Furthermore, as researchers discover the extent to which statistical gender differences translate into clinical significance, it is likely that support services will need modification to accommodate this new knowledge (Giarelli et al., 2010).
Differences in attitudes and behaviour towards females with Asperger Syndrome may also contribute to a delayed or missed diagnosis (Giarelli et al., 2010; Hartley & Sikora, 2009).
Attwood (2006) noticed that parents were more hesitant to seek a formal diagnosis if their daughters appeared to be functioning adequately, and that clinicians tended to hesitate in making a diagnosis unless the signs were quite conspicuous. This reinforces the observation made by Hully and Lamar (2006) that AS traits need to be exaggerated in females for a formal diagnosis.
In contrast to boys with AS, who are more often teased, ignored, or bullied by their male peers, girls more often experience support and even protection from some of their female peers, which could result in failure to recognize significant social impairments (Attwood, 2006). Beteta (2009) stresses that these friendships rely on the willingness of a girl’s peers, and accordingly, Rastam (2008) found that many girls with AS tended to have only one friendship that was usually tenuous in nature, and few peer relations overall.
In addition, the perception that many girls with Asperger syndrome seem to manage in social situations, can cause others to question the accuracy of diagnosis.
One result may be that when a girl exhibits behaviour common to AS, it is misunderstood as deliberate or wilful (Beteta, 2009), and she may not receive the necessary supports. Cooper and Hanstock (2009) found, for instance, that school staff continued to feel that Jane’s behaviour was “put on”, even after she received a diagnosis of Asperger syndrome.
Moreover, parents and teachers often connect social and functioning difficulties with intrinsic personality traits rather than to a developmental disorder like AS (Cooper & Hanstock, 2009). Specifically, they may misinterpret deficits in social skills, such as poor eye contact, as signs of shyness, embarrassment, or naivety (Wagner, 2006).
Girl’s social impairments, for example, are often misconstrued as stemming from their reserved natures, hence girls initially received an incorrect diagnosis of early onset anxiety disorder (Wilkinson, 2008).
In conclusion, there are a number of possible explanations for the 10:1 gender ratio in Asperger syndrome. Some think that the large number of diagnosed males accurately reflects natural sex differences in brain specialization, or points to sex-specific genetic susceptibility to AS (e.g., Baron-Cohen &Wheelwright, 2004; Jones et al., 2008).
Others believe that the current gender ratio misrepresents the incidence of AS in females (Thompson et al., 2003).
A biased perception of how AS presents may contribute to underdiagnosis (Attwood, 2006; Beteta, 2009), as many emphasize the overuse of a male prototype (e.g., Hully & Lamar, 2006; Thompson et al., 2003). Clinicians may attribute symptoms to psychiatric disorders more commonly seen in the general female population (Cooper & Hanstock, 2009; Rastam, 2008; Ryden & Bejolet, 2008), gender differences in phenotypic expression could mean that core impairments go unnoticed or are misinterpreted (Attwood, 2006; Beteta, 2009; Wilkinson, 2008), and the attitudes and behaviour of others towards females with AS may also contribute to underdiagnosis (Cooper & Hanstock, 2009; Wagner, 2006).
It is clear that one explanation for the uneven gender ratio is not sufficient on its own. The reasons are multifaceted and complex, and it is likely that other possibilities will emerge with additional research.
However, a greater understanding of gender differences in Asperger syndrome will likely play a large role in balancing the 10:1 ratio, as more females will receive an accurate diagnosis.
Written by A. MacMillan