Gender and Autism

Statistically, autism affects more males than females, but the reasons for this remain unclear. Are males inherently more likely to have autism, or does the way autism presents itself in females make it less easy to diagnose?

Below explores some of the issues related to autism and gender, including new research into autism in women and girls.

Women and girls on the Autism Spectrum

In recent years, questions have been raised about the ratio of males to females diagnosed as having an autism spectrum disorder (ASD). Overall the most recent studies suggest that the prevalence of autism spectrum disorder is about one in 100, but what of the male/female ratio? 

There is no hard evidence of numbers. Various studies, together with anecdotal evidence, have come up with male/female ratios ranging from 2:1 to 16:1. Whatever the true ratio, clinical referrals to a specialist diagnostic centre have seen a steady increase in the number of girls and women referred. Because of the male gender bias, girls are less likely to be identified with ASD, even when their symptoms are equally severe. Many girls are never referred for diagnosis and are missed from the statistics. Emphasis is placed on the different manifestations of behaviour in autism spectrum conditions as seen in girls and women compared with boys and men.

The different way in which girls and women present under the following headings have been identified below; social understanding, social communication, social imagination which is highly associated with routines, rituals and special interests. Some examples are:

  • Girls are more able to follow social actions by delayed imitation because they observe other children and copy them, perhaps masking the symptoms of Asperger syndrome (Attwood, 2007).
  • Girls are often more aware of and feel a need to interact socially. They are involved in social play, but are often led by their peers rather than initiating social contact. Girls are more socially inclined and many have one special friend.
  • In our society, girls are expected to be social in their communication. Girls on the spectrum do not ‘do social chit chat’ or make ‘meaningless’ comments in order to facilitate social communication. The idea of a social hierarchy and how one communicates with people of different status can be problematic and get girls into trouble with teachers.
  • Evidence suggests that girls have better imagination and more pretend play  (Knickmeyer et al, 2008). Many have a very rich and elaborate fantasy world with imaginary friends. Girls escape into fiction, and some live in another world with, for example, fairies and witches.
  • The interests of girls in the spectrum are very often similar to those of other girls – animals, horses, classical literature – and therefore are not seen as unusual. It is not the special interests that differentiate them from their peers but it is the quality and intensity of these interests. Many obsessively watch soap operas and have an intense interest in celebrities.

The presence of repetitive behaviour and special interests is part of the diagnostic criteria for an autism spectrum disorder. This is a crucial area in which the male stereotype of autism has clouded the issue in diagnosing girls and women.

As highlighted above, the current international diagnostic criteria do not give examples of the types of difficulties experienced by girls and women. In order to recognise the different behavioural manifestations, it is important to take a much wider perspective regarding the social, communication and imagination dimensions in addition to the special interests and rigidity of behaviour. The girls and women learn to act in social settings. Unenlightened diagnosticians perceive someone who appears able and who has reciprocal conversation and who uses appropriate affect and gestures as not fulfilling the criteria set out in the international classification systems. Therefore a diagnosis is missed. It is only by asking the right questions, taking a developmental history, and observing the person in different settings, that it becomes clear that the individual has adopted a social role which is based on intellect rather than social intuition. To quote: “The fact that girls with undiagnosed autism are painstakingly copying some behaviour is not picked up and therefore any social and communication problems they may be having are also overlooked. This sort of mimicking and repressing their autistic behaviour is exhausting, perhaps resulting in the high statistics of women with mental health problems.” (Dale Yaull-Smith, 2008).

It is important to prepare girls for a life of quality as adult women. Schools need better trained staff to recognise and address the needs of students on the autism spectrum and especially the more ‘subtle’ presentation in girls. Schools need to be more ‘girl-friendly’ with girl orientated personal, social skills classes. There needs to be a focus on the ‘hidden curriculum’ which directly teaches the skills that typically-developing girls learn indirectly and intuitively, such as the unwritten rules of girls’ social interactions. Girl orientated personal, social and health education should be part of the curriculum. Schools educating girls on the autism spectrum should focus on teaching independence and strategies to reduce vulnerability. They also need to address self-image, self-esteem and confidence building. Gender identity is a big issue for girls, as is emotional wellbeing and fostering mental health. Society has expectations of both men and women, but many women on the autism spectrum believe that these expectations are greater for women.

In the book ‘Asperger’s Syndrome for Dummies’ (Gomez de la Cuesta & Mason 2010), the authors touch on this issue and describe different ‘types’ of women on the autism spectrum. At work, women experience ‘a glass ceiling that is double glazed’ according to the authors. Women experience the same difficulties as other women, plus the difficulties experienced by women on the autism spectrum. These women often go into professions that are traditionally male-orientated. Harder (2010) has produced a booklet called ‘Illustrated glimpses of Aspergers for Friends and Colleagues’. This gives a valuable insight into the difficulties women on the autism spectrum experience at work and provides explanations to colleagues of the different ways in which such women perceive the world.

The difficulties in the diagnosis of girls and women arise if clinicians continue to use the narrow definitions set out in the International Classification Systems. It cannot be stressed enough that diagnosis and full assessment of needs cannot be carried out by following a checklist. Proper assessment takes time and detailed evaluation is necessary to enable a clinician to systematically collect information which not only provides a diagnostic label, but more importantly, a detailed profile of the person.

We wish to draw attention to the fact that many women with an autism spectrum condition are not being diagnosed and are therefore not receiving the help and support needed throughout their lives. Having a diagnosis is the starting point in providing appropriate support for girls and women in the spectrum. A timely diagnosis can avoid many of the difficulties women and girls with an autism spectrum disorder experience throughout their lives.

Dr Judith Gould and Dr Jacqui Ashton Smith
Good Autism Practice, May 2011 

Autism: Why do more boys than girls develop it?

Autism (including Asperger syndrome) appears to be more common among boys than girls. This could be because of genetic differences between the sexes, or that the criteria used to diagnose autism are based on the characteristics of male behaviour. However, our understanding is far from complete, and this will remain the case until we know more about the causes of autism.

Why are boys far more likely to develop autism than girls? 

There is strong evidence to suggest that there are more boys with ASDs (autism spectrum disorders) than girls. Brugha (2009) surveyed adults living in households throughout England, and found that 1.8% of males surveyed had an ASD, compared to 0.2% of females.

Hans Asperger originally believed that no girls were affected by the syndrome he described in 1944, although clinical evidence later caused him to revise this statement. In Kanner's 1943 study of a small group of children with autism there were four times as many boys as girls; and in their much larger study of Asperger syndrome in mainstream schools in Sweden in 1993, Ehlers and Gillberg found the same male to female ratio of 4:1. The ratio of male to females who use NAS adult services is approximately 4:1, and in those that use NAS schools it is approximately 5:1.

In epidemiological research Wing (1981) found that among people with high-functioning autism or Asperger syndrome there were as many as fifteen times as many males as females. On the other hand, when she looked at people with learning difficulties as well as autism the ratio of boys to girls was closer to 2:1. This would suggest that, while females are less likely to develop autism, when they do they are more severely impaired.

It is difficult to explain why the sexes should be affected differently by autism 

Attwood (2000), Ehlers and Gillberg (1993) and Wing (1981) have all speculated that many girls with Asperger syndrome are never referred for diagnosis, and so are simply missing from statistics. This might be because the diagnostic criteria for Asperger syndrome are based on the behavioural characteristics of boys, who are often more noticeably "different" or disruptive than girls with the same underlying deficits. Girls with Asperger syndrome may be better at masking their difficulties in order to fit in with their peers, and in general have a more even profile of social skills. Gould and Ashton-Smith (2011) say that because females with ASDs may present differently from males, diagnostic questions should be altered to identify some females with ASDs who might otherwise be missed. 

Another hypothesis (Wing 1981) is based on evidence that, in the general population, females have better verbal skills, while males excel in visuo-spatial tasks. There may be a neurological basis for this, so that autism can be interpreted as exaggeration of "normal" sex differences. But environmental and social factors may also play a part in sex differences in ability, which means that no direct analogy can be drawn between the poorer verbal skills of boys and the higher incidence of autism in males.

In 1964 Bernard Rimland pointed out that, overall, males tend to be more susceptible to organic damage than girls, whether through hereditary disease, acquired infection or other conditions. Since it is now almost universally accepted that there is an organic cause for autism, it should not be surprising that boys are more vulnerable to it than girls.

In recent years researchers have put forward a genetic explanation for the differences. Skuse (2000) has suggested that the gene or genes for autism are located on the X chromosome. Girls inherit X chromosomes from both parents, but boys only inherit one, from their mothers. Skuse's hypothesis is that the X chromosome which girls inherit from their fathers contains an imprinted gene which "protects" the carrier from autism, thus making girls less likely to develop the condition than boys.

This theory has been used to support Asperger's view that autism and Asperger syndrome are at the extreme end of a spectrum of behaviours normally associated with "maleness". Such behaviours can be extremely useful in areas of life such as engineering and science, where attention to detail and single-mindedness may be more valuable than social skills, for example.

Lord and Schopler (1987) have outlined several possible mechanisms for the transmission of autism on the sex-linked X chromosome, and also for autosomal transmission (ie involving non-sex chromosomes. However, these are merely theoretical models and in fact researchers are still a long way from identifying a simple genetic cause for autism. It is likely that several genes on different chromosomes will be found to be associated with autism. This means that Skuse's theory, based on the X chromosome alone, may not represent the full picture.

Various theories have been put forward for the excess of males with autism and Asperger syndrome, but the picture is far from complete and until we have a fuller understanding of the causes of autism, it is unlikely that a proper explanation can be reached.


Asperger, H. (1944). Die autistischen Psychopathen im Kindesalter. Archiv fur Psychiatrie und Nervenkrankheiten, 117, pp. 76-136

Attwood, T. (2000). Asperger syndrome: Some common questions: Do girls have a different expression of the syndrome? Available from:

Brugha, T. (2009). Autism spectrum disorders in adults living in households throughout England: report from the Adult Psychiatric Morbidity Survey 2007. The NHS Information Centre for Health and Social Care. Available from:

Ehlers, S. & Gillberg, C. (1993). The Epidemiology of Asperger syndrome. A total population study. Journal of Child Psychology and Psychiatry, 34 (8), pp. 1327-1350

Gould, J. & Ashton-Smith, J. (2011). Missed diagnosis or misdiagnosis: girls and women on the autism spectrum. Good Autism Practice, 2011, Vol.12 (1), pp. 34-41

Kanner, L. (1943). Autistic disturbances of affective contact.Nervous child, 2, pp. 217-50

Lord, C. & Schopler, E. (1987). Neurobiological implications of sex differences in autism. In: Schopler, E. & Mesibov, G.M. (Eds.). Neurobiological issues in autism. New York: Plenum Press, pp. 191-211

Rimland, B. (1964). The etiology of infantile autism. In: Infantile autism: the syndrome and its implications for a neural theory of behaviour. New York: Appleton-Century-Crofts. p. 54

Skuse, D.H. (2000). Imprinting the X-chromosome, and the male brain: explaining sex differences in the liability to autism. Pediatric Research, 47 (1), pp. 9-16

Wing, L. (1981). Sex ratios in early childhood autism and related conditions. Psychiatry Research, 5, pp129-37