Many more boys are diagnosed with autism every year than girls. According to the Centers for Disease Control and Prevention, the disorder is 4.5 times more common among boys than girls. Boys appear to be more vulnerable to the disorder, but there is some evidence that the gender gap may not be as wide as it appears.
That's because the symptoms of autism are often less obvious in girls than they are in boys. Girls can be better at blending in, says Dr. Louis Kraus, a psychiatrist at Rush University Medical Center in Chicago, who specializes in autism.
"Girls tend to want to socialize and be part of a group," he says, even though it may be awkward. Boys, on the other hand, "tend to be more isolative," says Kraus.
That makes it more likely that autism in boys is spotted at an earlier age. Girls, on the other hand, may not get diagnosed or may be diagnosed later because their symptoms don't stand out, Kraus says. This means girls don't get the early intervention that they need.
This was the case for Haley Wittenberg, who lives in Los Angeles. She's the youngest of four siblings, and was diagnosed with autism about a year ago, at the age of 19. The diagnosis was a relief, she says because it finally put a name to what she'd been feeling for years — that she was different from her siblings and her classmates.
"I would always play sports with the boys when I was little, because it was easier for me and they didn't talk as much," Haley says.
When she was a baby she never wanted to be cuddled or snuggled, says Haley's mom, Lonnie Wittenberg. Haley also didn't make eye contact. "I was always saying look at me, look at me," her mom says. Haley didn't like noisy, crowded places like Disneyland, and she had a hard time being "spontaneous." But for the most part these seemed like "quirks," Lonnie Wittenberg says. "Nothing screamed autism."
Autism spectrum disorder (ASD) is a complex developmental disorder, characterized by repetitive, compulsive behaviors, a lack of interest in social interaction and little or no eye contact. There is no medical test to diagnose autism. Doctors look at the child's behavior and development to make a diagnosis.
It turns out Haley's situation is pretty typical for high-functioning autistic girls, whose symptoms can be less noticeable.
Girls appear to have mastered what some call "social camouflaging," says Amanda Gulsrud, clincial director of the Child and Adult Neurodevelopmental Clinic at University of California, Los Angeles. Gulsrud develops school interventions for children with autism. The interventions are based, in part, on earlier research done by colleagues at UCLA, who did a study looking at how autistic boys and girls with autism interact with their non-autistic peers on the school playground. The boys clearly stood out as being different, Gulsrud says. They were very isolated from the other boys, who were in a large group playing sports. The boys with autism were the ones "circling the perimeter of the yard, or off by the tree in the back."
Girls with autism, on the other hand, didn't stand out as much, she says. They stuck close enough to the other girls to look as if they were socially connected, but in reality they were not really connecting. "They were not having deep, meaningful conversations or exchanges," Gulsrud says. They were flitting in and out of that social connection.
Girls with autism tend to be quiet and "behave more appropriately," says Marisela Huerta, a psychologist with the Weill Cornell Medical College. She co-authored a survey of clinicians who specialize in autism. The clinicians were asked to compare the severity of symptoms in females, compared to males. Seventy percent of them reported clear gender differences in autism symptoms, with boys more likely to exhibit repetitive behaviors, fixated interests and being less likely to engage in social interactions. Girls tend to be more verbal and socially interactive, at least at younger ages. This may be why parents and teachers often don't pick up on girls' symptoms and don't refer as many girls for evaluation.
Another characteristic of autism is a tendency toward compulsive behavior. And here again, girls and boys can differ quite a bit, says psychiatrist Kraus. Boys can get obsessed with objects like rocks, for example, to the point that they carry pounds and pounds of them around in a backpack and talk about them endlessly. "This fixation can drive them away from socializing," Kraus says, whereas girls' obsessions don't seem to ostracize them from social development. They may get fixated on collecting shells, for example, but this behavior seems "endearing and culturally acceptable," Kraus says.
Researchers are trying to learn more about sex differences in autism. Child pyschologist Kevin Pelphrey, director of the Autism and Neurodevelopmental Disorders Institute at George Washington University, is the father of two children with autism. He's leading an NIH-funded study on girls with autism, focusing on genes, brain function and behavior through childhood and adolescence.
Preliminary findings suggest there are differences in the brains of girls and boys with the disorder. Brain imaging shows that autistic girls seem to have less of a disruption in the area of the brain that processes social information, Pelphrey says. Girls may be more likely to understand social expectations, even if they can't fully meet them. "This can be stressful for girls," Pelphrey says.
A late diagnosis of autism is a setback for any child, psychiatrist Kraus says, pointing to research that shows the earlier the diagnosis and intervention, the better the outcome.
"You can always make up academics. That's never a huge worry if you fall a little behind with academics," he says. "What is much, much harder to do is make up social development."
Today, there are an increasing number of academic and community programs geared to help autistic teens and young adults catch up on their social development. Haley Wittenberg is taking part in one at UCLA called PEERS. She's learning how to approach a group of people she wants to get to know, how to start and maintain a conversation and how to make friends and keep them.
"They gave me the tools that I could use in situations so I wouldn't feel so exhausted after," Haley says. "Now I can hang out with the same people for a lot longer and a lot more often." She's even a bit more spontaneous, she says with a giggle, willing to "hang out" with only a few minutes notice. Conversations are easier and her social life is more active. Overall, Haley says her life has really improved.