Although there has been a dramatic increase in the recognition of autism spectrum disorders over the past decade, a significant gender gap has emerged in the diagnosis of milder forms, such as high functioning autism and Asperger syndrome. Statistics indicate that while boys are being referred and identified in greater numbers, this is not the case for girls.
Girls are also diagnosed at later ages compared to boys. In this article, the author discusses possible explanations for the under identification of girls with high functioning autism and Asperger syndrome. A case vignette is used to illustrate the gender differences relevant to the understanding and timely diagnosis of girls with this autism spectrum condition. Asperger syndrome is an autism spectrum disorder characterized by problems in social relatedness, empathic communication and understanding, and circumscribed interests in the presence of generally age appropriate language acquisition and cognitive functioning (Volkmar & Klin, 2000).
Students with Asperger syndrome often experience problems related to their social deficits and are at risk for academic underachievement, school drop-out, peer rejection and internalizing problems such as anxiety and depression(Safran, 2002; Wilkinson, 2005). Although there has been a dramatic increase in the number of children diagnosed with autism spectrum disorders over the past decade, a significant gender gap has emerged in the identification of milder forms, such as high functioning autism and Asperger syndrome. Statistics indicate that while boys are being referred and identified in greater numbers, this is not the case for girls (Attwood, 2006; Ehlers & Gillberg, 1993; Wagner, 2006).
For example, referrals for evaluation of boys are ten times higher than for girls (Attwood, 2006). Girls are also diagnosed with autism spectrum disorders at later ages relative to boys (Goin-Kochel, Mackintosh, & Meyers, 2006). This gender gap raises serious questions because many female students with Asperger syndrome are being overlooked and may not receive the appropriate educational supports and services. The consequences of a missed or late diagnosis include social isolation, peer rejection, lowered grades, and a greater risk for mental health and behavioral distress such as anxiety and depression during adolescence and adulthood.
Why are fewer girls being identified? Why do parents of girls experience a delay in receiving a diagnosis? Are there gender differences in the expression of the disorder? Answers to these questions have practical implications in that gender specific variations may have a significant impact on identification practices and the provision of educational services for children with autism spectrum disorders (Thompson, Caruso, & Ellerbeck, 2003).
Although few studies have examined gender differences in the expression of autism, we do have several tentative explanations for the under identification and late diagnosis of girls with Asperger syndrome. This article discusses these possibilities and provides a case vignette to illustrate the gender differences relevant to the understanding and timely diagnosis of girls with Asperger syndrome.
Gender role socialization is critical to understanding why girls with Asperger syndrome are being under identified (Faherty, 2006). Since females are socialized differently, autism spectrum disorders may not manifest in the same way as typical male behavioral patterns (Bashe & Kirby, 2005). For example, girls might not come to the attention of parents and teachers because of better coping mechanisms and the ability to “disappear” in large groups (Attwood, 2007). Girls on the higher end of the spectrum also have fewer special interests, better superficial social skills, better language and communication skills, and less hyperactivity and aggression than boys (Gillberg & Coleman, 2000). Likewise, girls are more likely than boys to be guided and protected by.
When I think of my earliest years, I recall an overwhelming desire to be away from my peers. I much preferred the company of my imaginary friends- -Liane Holliday Willey (1999)
Same gender peers have special interests that appear to be more gender appropriate (Attwood, 2006).
These characteristics lessen the probability of a girl being identified as having the core symptom of autism spectrum disorder: an impairment in social skills. In fact, it may be a qualitative difference in social connectedness and reciprocity that differentiates the genders (Attwood, 2007; Kopp & Gillberg, 1992). As a result, parents, teachers, and clinicians may not observe the obvious characteristics associated with the male prototype of higher functioning autism spectrum conditions such as Asperger syndrome (Kopp & Gillberg, 1992; Nyden, Hjelmquist, & Gillberg, 2000).
- Although girls may appear less symptomatic than boys, both genders share similar profiles. Research suggests that when IQ is controlled, the main gender difference is a higher frequency of idiosyncratic and unusual visual interests and lower levels of appropriate play in males compared to females (Lord, Schopler, & Nevicki, 1982). As a result, the behavior and educational needs of boys are much more difficult to ignore and are frequently seen by teachers and parents as being more urgent, further contributing to a referral bias (Kopp & Gillberg, 1992).
- Over reliance on the male model with regard to diagnostic criteria contributes to a gender “bias” and under diagnosis of girls (Kopp & Gillberg, 1992; Nyden et al., 2000). Clinical instruments also tend to exclude symptoms and behaviors that may be more typical of females with autism spectrum disorders.
Conclusion and Recommendations
Asperger syndrome may have a different profile in girls than boys, which in turn, might not be recognized as an autism spectrum disorder (Thompson et al., 2003). While the gender gap in Asperger syndrome has yet to be empirically investigated, if girls do process language and social information differently than boys, then clinical and educational interventions based largely on research with boys may be inappropriate.
As a result, girls may receive less than optimal academic and behavioral interventions and not realize their potential. Further research is urgently needed to examine the similarities and differences between males and females to determine whether the diagnostic definition of Asperger syndrome is valid for both boys and girls (Attwood, 2007). If gender specific variations do exist, then the predictive validity of the diagnosis and developmental course may well differ between the sexes.
In the meantime, educators and school personnel should question the presence of an autism spectrum disorder in female students who may be referred for internalizing problems such as anxiety or depression. Additionally, when a girl presents with a combination of social immaturity, preservative or circumscribed interests, limited eye gaze, repetitive, social isolation, high levels of anxiety and attention problems, and is viewed as “passive” or “odd” by parents, teachers or peers, the likelihood of an autism spectrum disorder should be considered (Wagner, 2006).