Liane Willey watched from behind a two-way mirror as doctors at the University of Kansas performed a series of psychological tests on her 5-year-old daughter. From the day the girl was born, Liane had worried about the child's behavior: as an infant, she would not suckle. As a toddler, she bit other children and refused to let anyone hug her. Doctors had continually assured the young mother that her daughter was normal, if a bit quirky. But with each passing year, 'quirky' had become less apt a description. By the age of 5, she had no friends and a profound obsession with monkeys. "If another kid came to school with a toy monkey or something with a monkey picture on it, she would freak out," Liane says. "She would try to take it away from the other kid, because she didn't get that not everything 'monkey' was hers." Liane had been a quirky child herself, and knew the difficult path that lay ahead for her daughter. "Growing up, I tried everything—psychotherapy, group therapy, antidepressants—none of them gave me a better sense of the world or my place in it," she recalls. "For her, I wanted something that would actually work, and I wanted them to put a name to the angst once and for all." Doctors were hoping the psychological tests would yield-up some clues.
The "Sally-Anne" test involved a simple skit: 'Sally' put a marble in the basket and then walked away. Once she was gone, 'Anne' took the marble out of the basket and put it in a box. When 'Sally' returned, the doctors asked where she would look for her marble. Anyone over the age of 5 is expected to know that Sally would look in the basket first, because she doesn't know that her marble has been moved. Expecting Sally to look in the box first suggests that the test-taker doesn't understand that other people don't know everything they know, and vice versa. Psychologists refer to this as a "theory of mind," and people who fail the Sally-Anne test are said to lack one, meaning they can't anticipate other people's thoughts and feelings. Liane's daughter failed the Sally-Anne test, along with every other assessment meant to screen for Asperger's syndrome, a high-functioning autism spectrum disorder, which the doctors promptly diagnosed her with. The good news was that they had caught it early.
It's not uncommon for girls with Asperger's to go undiagnosed well into adulthood. Like heart disease, this high-functioning autism spectrum disorder is 10 times more prevalent in males, so doctors often don't think to look for it in females. But some experts have begun to suspect that unlike heart disease, Asperger's manifests differently, less obviously in girls, and that factor is also causing them to slip through the diagnostic cracks. This gender gap may have implications for the health and well-being of girls on the spectrum, and some specialists predict that as we diagnose more girls, our profile of the disorder as a whole will change. Anecdotally, they report that girls with Asperger's seem to have less motor impairment, a broader range of obsessive interests, and a stronger desire to connect with others, despite their social impairment.
But much more research is needed before those anecdotes can be marshaled into a coherent picture. "Ultimately, we might want to look for different symptoms in girls," says Katherine Loveland, a psychiatry professor and autism researcher at the University of Texas in Houston. "But we have a lot more questions than answers at this point." Answering those questions has proven a tricky proposition: to draw any real conclusions, many more girls will have to be studied. And that means more of them will have to be diagnosed in the first place.
Anyone who knows a boy with Asperger's syndrome might tell you that the disorder (characterized by obsessive interests and an inability to connect with others) is impossible to miss. For starters, the things most boys get obsessed with are difficult to shrug off as quirky. Imagine, for example, a 7-year-old boy with encyclopedic knowledge of vacuum cleaners or oscillating fans but almost no friends or playmates.
Now, replace oscillating fans with something more conventional - say horses or books - and imagine a girl instead of a boy. A horse obsession, even one of frightening intensity, might fly under the radar. "Girls tend to get obsessed with things that are a little less strange," says Elizabeth Roberts, a neuropsychologist at the Asperger Institute at the New York University Child Study Center. "That makes it harder to distinguish normal from abnormal." That observation is consistent with a 2007 study of 700 children on the spectrum, which found that girls' obsessive interests reflected the interests of girls in the general population; the same was not true for boys.
In addition to more socially acceptable obsessions, Roberts says, the Aspie girls she sees are more adept at copying the behaviors, mannerisms and dress codes of those around them, than Aspie boys tend to be. "From my personal experience, they seem to have a greater drive to fit in than boys with Asperger's do," she says. "So they spend a lot of time studying other girls and trying to copy them." When social settings change, this can spell disaster. "As you move from high school to college, or from one group of friends to another, you have a whole new set of rules to learn," said one Aspie woman who asked not to be named. "Not only do you lose your own identity, but if you end up surrounded by the wrong people—mimicking their behavior without understanding the motivations behind it can lead to big trouble."
Of course, it's not just different symptoms that stymie diagnosis—cultural conditioning may also play a role. What looks like pathological social awkwardness in a little boy can seem like mere bashfulness or just good old-fashioned manners in a little girl. "We tend to notice shyness in boys as 'off,'" says Loveland. "In girls, we can almost see it as a good trait." And while boys are often diagnosed when they begin expressing their frustration as aggression and find themselves in trouble at school, girls —even Aspie girls—learn to internalize their feelings, not to act out, which can make them more anxious and less noticeable at the same time.
But even as they effectively mask Asperger's in girls, social mores might also make the disorder more harrowing for them. As they approach adolescence, girls face greater pressure to be sympathetic and empathetic than boys do. "By the time girls reach junior high, their social networks have become extraordinarily complex, and Aspie girls can't keep up with all the nuances," says Janet Lainhart, a doctor at the University of Utah's Brain Institute. "Boys struggle socially as well, but their peers mature much slower so their inability to empathize is seen as more forgivable."
Not everyone is persuaded that the symptoms of Asperger's differ between boys and girls. Ami Klin, director of Yale's autism research group cautions that no Asperger's trait can be defined as gender-specific quite yet. "It's a possibility," he says. "But I don't know anyone who has tested it and I can think of many exceptions to any rule you come up with about what narrow interests or other traits each gender has."
What everyone does seem to agree on is that without diagnosis, girls are unlikely to get the support—including special education and behavioral therapy—that has proven so helpful to boys with Asperger's. Even worse, their desperation for human interaction—combined with their inability to gauge the intentions of those around them—can make girls with Asperger's easy prey for sexual predators. "That is a real distinction and my real concern for girls on the spectrum," says Klin. "That they will be more susceptible to rape, abuse and drug addiction because of their social deficiencies and because they aren't getting the right guidance."
Despite the urgent need for more research, Klin says that scientists who study ASDs have effectively orphaned this population. Because there are so few of them, girls are often yanked from studies altogether so that they don't muddy up the data. As a result, only a very small body of work addresses the Asperger's gender gap, even though such studies could lead to better diagnosis of both autism and Asperger's.
Preliminary genetic analyses suggest that autism may be caused by different genes in each gender; and at least one MRI study has found differences in the brain anatomy of boys and girls on the spectrum. Simon Baron-Cohen, a renowned autism researcher, has shown that high levels of fetal testosterone may also play a role. But that work has yet to be replicated, mainly, say Loveland and others, due to a lack of funding or interest. "A lot of people see Baron-Cohen's work as 'politically incorrect,'" says Loveland. "Any time you start talking about a biological basis of sex differences, you are looking at controversy."
Meanwhile, many schools and clinics that work with children on the spectrum have begun forming girls-only clubs in an effort to build better support systems for girls with Asperger's. Lainhart has created a group at her Utah practice. The first things her girls, who range in age from early teens to late 20s, wanted to know: how to plan a dinner party and how to hold a dance. "They really want to understand how to do these very-female things, they just need the guidance to get there," she says.
Of course, getting that guidance depends on getting the right diagnosis early on. And it turned out that Liane's daughter wasn't the only one to fail the Sally-Anne test that afternoon. Liane herself had not been able to distinguish between what she knew and what Sally knew. Doctors diagnosed her right alongside her daughter. Liane says that diagnosis changed everything for her. "It was like a light bulb went off," she says. "I was able to seek out the right kind of treatment, and after a lifetime of mimicking others, finally find my own identity." And early diagnosis has helped her daughter (now a healthy teenager) avoid many of the pitfalls that Liane herself fell prey to. "Her experience has been totally different from mine," she says. "She's had special education and behavioral therapy from the time she was a young girl, and if I introduced you to my three daughters today, you wouldn't be able to tell which one has Asperger's."