Various studies have researched rates of autism in males compared to females, with the most recent data estimating that autism is at least three times as common in boys than it is in girls.

One theory to explain this diagnostic imbalance is that men are more likely to have a biological predisposition to autism compared to women. However, contemporary research paints a rather different picture.

Many scientists and autism experts now believe that there are far more autistic women and girls than we realise, but many are ‘flying under the radar’, remaining undiagnosed for long periods of time, or sometimes, their entire lives.

There are a number of ways to explain this hypothesis, with the three main arguments being: that the autism diagnostic criteria are geared towards men, that autistic women are better at “masking” than autistic men, and that autistic women often do not fit autism stereotypes typically associated with the condition.

Are the autism criteria geared towards men?

Because autism has long been thought to be more common in boys compared to girls, early autism research only used male participants. This has led to an intense gender-bias in both research and diagnosis that persists to this day.

As a result of this research, many experts believe the autism diagnostic criteria are geared towards men, which means women are often missed when undergoing assessment. Paige Layle, who is autistic herself, has created a series of educational videos explaining how autism can present differently in girls and women, and the problems this can cause.

In one video, she explains that a lot of the questions asked during assessments are based on ‘male’ topics. For example, when asking about hyper-fixations or limited interests, the doctor might ask: “Is your child focused on one specific sport or a specific player from that one sport?” Girls might answer “no” to this question, but it’s not because they don’t have a limited interest, it’s because they’re fixated on something else like horses or dolls, for example. 

Although these tests have been revised in recent years, experts say many questions are still based on gender stereotypes or an overly simplistic concept of sex differences. This means that when women and girls have a special interest in a more ‘feminine’ area, the level of interest if often missed and their autism remains undiagnosed.

As a result, women and girls are often diagnosed with autism far later than their male counterparts, with research suggesting that just 20% of girls are diagnosed with autism spectrum condition (ASC) prior to the age of 11, compared to 50% of boys.

Late diagnoses can trigger the onset of other mental health disorders, such as depression and anxiety, as it becomes harder to keep up with social rules and complex social relationships.

What is masking and how does it affect autistic girls?

In order to cope in social situations, many autistic girls and women begin to ‘mask’ their autistic traits. ‘Masking’ or ‘camouflaging’ is when the individual artificially performs behaviours which are deemed to be socially acceptable (by neurotypical standards) or hides behaviours that may be viewed as socially unacceptable.

Camouflaging strategies include imitations such as: forcing facial expressions, like smiles; copying gestures and mannerisms; pre-preparing conversations topics or jokes; and imitating eye contact.

Autistic women are typically thought to be better at masking compared to men, making it harder for them to receive a diagnosis. They are also thought to display subtler characteristic behavioural presentation than men and boys, or exhibit other behaviours that aren’t ‘stereotypically’ autistic (see below).

There are various reasons why autistic people mask, but it is often motivated by a sense of alienation, causing the individual to exhibit behaviours which allow them to fit in and connect with their peers and avoid negative consequences, such as bullying and teasing. However, these behaviours and techniques come at a cost, and if they go on for too long, the person may start to lose their sense of self.

Constantly imitating others and hiding ‘natural’ behaviours requires a huge amount of cognitive effort and can be exhausting for the individual. This can eventually lead to a sensory or emotional overload causing a meltdown.

Masking also often leads to ‘autistic burnout’ where the psychological exhaustion takes its toll, leading to the development of depression, anxiety or other mental health disorders.

Sadly, it is often only when autistic women reach crisis point that they receive a diagnosis, leaving many with lasting trauma and other mental illnesses. Scientists and autism experts therefore strongly discourage masking due to the risks posed to mental health, wellbeing and identity development.

Autistic women don’t always fit autism stereotypes

Because autistic women and girls tend to be very good at masking, they often do not fit the stereotypes typically associated with autism. This, combined with the idea that autism research historically focused on men, contributes to late or missed diagnoses.

Most of the behaviours and characteristics associated with autism are therefore typically masculine, constructing a male-based behavioural characterisation of autism. Paige describes this concept in another one of her video's, explaining that autistic people are generally thought to be anti-social and are often not very good at giving eye contact – this is of course, is a sweeping generalisation and not true of every autistic person, male or female.

However, as an autistic woman, Paige says she gives “too much” eye contact and is “very good” in social situations, which meant she didn’t fit in with the ‘male model’ of autism. In fact, research has found that women with autism often show more social interest, have heightened emotional awareness and are better at creating friendships than autistic men.

Another study found that autistic girls exhibit less repetitive and restricted behaviour than boys do, with biological brain differences between the sexes helping to explain the discrepancy.

Research and studies which include women are therefore urgently needed to make it easier to diagnose autism in women and prevent crises occurring and the development of mental illnesses such as anxiety and depression. Until this happens, countless women and girls will continue to ‘fly under the radar’, posing an enormous risk to mental health and wellbeing.