WHY IS AUTISM MORE COMMON IN BOYS?

The ratio of males to females is about four to one.

Girls with Asperger’s may be more difficult to recognize due to coping and camouflaging mechanisms, which can also be used by some boys. One of the coping mechanisms is to learn how to act in a social setting. The clinician perceives someone who appears able to develop a reciprocal conversation and use appropriate affect and gestures during the interaction. However, further investigation and observation at school may determine that the child adopts a social role and script, basing her persona on the characteristics of someone who would be reasonably socially skilled in the situation and using intellectual abilities rather than intuition to determine what to say or do.

An example of a camouflaging strategy is to conceal confusion when playing with peers by politely declining invitations to join in until sure of what to do, so as not to make a conspicuous social error. The strategy is to wait, observe, and only participate when sure of what to do by imitating what the children have done previously. If the rules or nature of the game suddenly change, the child is lost.

Girls with AS can develop the ability to ‘disappear’ in a large group, being on the periphery of social interaction – ‘on the outside looking in’. There can be other strategies to avoid active participation in class proceedings, such as being well-behaved and polite, thus being left alone by teachers and peers, or tactics to passively avoid cooperation and social inclusion at school and home, as described in a condition known as Pathological Demand Avoidance.

A girl with AS is less likely to be ‘fickle’ or ‘bitchy’ in friendships in comparison to other girls and is more likely than boys to develop a close friendship with someone who demonstrates a maternal attachment to this socially naive but ‘safe’ girl. The characteristics reduce the likelihood of being identified as having one of the main diagnostic criteria for AS, namely a failure to develop peer relationships. With girls, it is not a failure but a qualitative difference in this ability. The girl’s problems with social understanding may only become conspicuous when her friend and mentor move to another school.

The language and cognitive profile of girls with AS may be the same as those of boys, but the special interests may not be as idiosyncratic or eccentric as can occur with some boys. Adults may consider there is nothing unusual about a girl who has an interest in horses, but the problem may be the intensity and dominance of the interest in her daily life: the girl may have moved her mattress into the stable so that she can sleep next to the horse.

If her interest is dolls, she may have over 50 Barbie dolls arranged in alphabetical order, but she would rarely include other girls in her doll play.

In conversation, boys may sound like ‘little professors’ with an advanced vocabulary and can provide many interesting (or boring) facts. Girls with AS can sound like ‘little philosophers’, with an ability to think deeply about social situations. From an early age, girls with AS have applied their cognitive skills to analyze social interactions and are more likely than boys with AS to discuss the inconsistencies in social conventions and their thoughts on social events.

The motor coordination problems of girls may not be so conspicuous in the playground, and they are less likely to have developed conduct problems that can prompt a referral for a diagnostic assessment for a boy. These parents, teachers, and clinicians may fail to see any conspicuous characteristics of AS in females.

In actual clinical practice, an astute clinician may find that the ratio of men to women adults is as low as 2 to 1. With increasing maturity, adults are prepared to get help, especially when there have been long-term and unresolved problems with emotions, employment, and relationships. Another pathway is when a woman has a child with AS and recognizes that she has a similar character.

One reason why the prevalence of Asperger’s Syndrome in girls and women is so low in comparison to boys and men may be the fundamental lack of awareness of what Asperger’s Syndrome “looks like” in females. Traditional frameworks may indicate that the female with Asperger’s Syndrome is just shy, quiet, and perfect at school, so her parents must be exaggerating. But she could also be tomboyish, moody, overly competitive, aloof, Gothic, depressed, anxious, or a perfectionist, masking her autistic social issues.

Research into fetal testosterone examines its effects on brain development and postnatal behaviour. Cambridge has analyzed the effects of prenatal testosterone levels, produced by the fetus and measured via amniocentesis during the first trimester of pregnancy, on autistic behaviour. Fetal testosterone shapes brain development to alter an individual’s cognitive profile by binding to androgen receptors in the brain. The amygdala is one region that is rich in such receptors. Cambridge researchers have shown that higher prenatal testosterone levels are associated with reduced social skills but superior attention to detail in infants.