Why is Autism More Common in Boys? Causes & Theories

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Common Characteristics of Boys With Autism

Autism, a developmental disorder that primarily affects communication and behavioral skills, is diagnosed four times more often in boys than in girls. While professionals are not entirely sure why autism statistics show that the disorder appears to skew highly toward the male gender, there are some theories that attempt to explain the common phenomenon of autism in boys. One possibility is that autism has a genetic component that is more likely to affect the male brain. Some experts suggest that boys display symptoms and characteristics of autism in a more obvious manner than girls do, resulting in a disparity in the number of diagnoses given.

The autism-related characteristics that are most often associated with boys are aggression, hyperactivity, and social immaturity. Boys who are on the autism spectrum often display negative behaviors in an external way while at school or at home, making the disorder easier for teachers and parents to recognize and seek treatment for. Boys are much less likely than girls to mask their autistic traits by copying the social behaviors that are exhibited by neurotypical children. This theory suggests that autism may not in actuality occur more frequently in boys, but that girls are often underdiagnosed due to their tendency to internalize certain symptoms. (1)

Genetic and Gender Differences Associated With Autism

One theory about why autism appears to be more common in boys suggests that the disorder stems from one or more defective genes on the X chromosome. This genetic theory, proposed by D.H. Skuse, is based on the idea that boys, who have only one X chromosome, are more susceptible to autism because they do not have the protection of a second normal X chromosome as found in girls. Other genetic-based autism theories examine the possibility that boys are more susceptible to the disorder due to the mutations of several genes located on different non-sex chromosomes. (2)

Some scientists and researchers speculate that the structure of the male brain, which tends to be wired in a technical rather than an emotional sense, is more conducive to the displaying of externalized autistic traits. Girls who have an autism spectrum disorder may be better able to conceal their condition due to a higher development of the brain centers that regulate concepts such as social awareness and the capacity to empathize with others.

Presently, the greater incidence of autism in boys cannot be fully explained by any conclusive research findings on the part of scientists or mental health professionals. It is hoped that continued studies on this topic will provide insight as to whether autism can be definitively linked to gender differences.


1. Autism Spectrum Disorder Fact Sheet–https://www.autism-help.org/points-gender-imbalance.htm

2. National Autistic Society–https://www.autism.org.uk/nas/jsp/polopoly.jsp?d=1049&a=3370