You may have seen the movie Rain Man about a man who had savant syndrome and was remarkably adept at calculations. But he had social and communication impairments associated with autism as well. He was what is known as an "autistic savant," meaning he had both autism and savant syndrome.
Yet only about 10 percent of people with autism have savant syndrome. Many people mistakenly believe that savant syndrome is very common in autism, or even that savant syndrome and autism are one and the same.
People with savant syndrome have unique and extraordinary abilities in memorization, calculation (math and calendar), music, art, and language. People with autism have social impairments, communication difficulties, and restricted, repetitive, and stereotyped patterns of behavior.
According to a recent review, there are many myths and misconceptions surrounding savant syndrome. For example, not all savants are autistic; in fact, about 25% have some other cognitive, neurologic or developmental disability other than autism as the disability which underlies the savant skills.
And not all savants are born with that condition (congenital savants). In some people, savant syndrome can be precipitated later in life by brain injury, stroke, or dementia in which case it is called "acquired savant syndrome." For example, not all savants have autism as the underlying disability; in fact, about 25 percent have some other cognitive, neurologic, or developmental disability other than autism.
People with autism fall within a “spectrum” of abilities, ranging from mild to severe. Some have what is known as “high-functioning” autism, meaning they tend to have higher IQs. But high-functioning autism is not the same as savant syndrome. And savants can have either low or high IQ’s, despite their remarkable abilities in certain areas.
“IQ can vary widely in savant syndrome from extremely low to superior,” says Darold Treffert, MD, a psychiatrist at St. Agnes Hospital in Fond du Lac, WI, who wrote the recent review on savant syndrome. Treffert has studied savant syndrome for many years, and he was a consultant to the movie Rain Man. “Most have IQ’s in the 50-70 range but some have superior IQ -- just as is the case with the normal distribution curve of IQ in all of us—from very low to superior.”
The average range for IQ is 90-110. High average is 111-120, and superior IQ is 121 and above. Scores in the 80-89 range are low average, 70-79 are borderline, and below 70 are extremely low.
Treffert says the most common type of savants, whether they are autistic or not, have what are known as “splinter skills.” For example, they may have an “obsessive preoccupation with and memorization of music and sports trivia, birthdays, license plate numbers, historical facts, train or bus schedules, navigation abilities or maps,” he explains. Or, they may have special skills in music or art, and are known as “talented savants.”
Certain types of savant syndrome seem uniquely uncanny. For example, some savants have a highly unusual “triad” of symptoms – mental impairment (which can be from autism), impaired vision, and musical genius. This type of savant happens “disproportionately” among savant cases, according to Treffert, and includes some famous musicians such as “Blind Tom,” a former slave who became a popular composer, pianist, and performer in the 1800s.
A misconception about savants is that they are robotic and incapable of having original abilities, according to Treffert. For example, they may be able to listen to a song once and play it perfectly, but many people think they can’t compose their own music.
“Savants are not mere ‘copy machines’ with great memorization abilities,” he says. “Over time most savants tire of mere repetition and begin to ‘improvise’ first and then finally do create something entirely new.”
Savants also are not geniuses. A genius is someone who has special skills but no underlying disability, such as autism or intellectual impairment.
“A savant by definition has special gifts superimposed on some underlying disability,” Treffert explains.
Sometimes savant syndrome is confused with Asperger syndrome, a "high functioning" type of autism which causes social impairment, communication difficulties and strict adherence to routine. Some people with Asperger syndrome do have high IQs, but that does not automatically make them savants, since savant syndrome requires some special skill or "giftedness," he says.
For example, Temple Grandin, a professor of animal science at Colorado State University and an outspoken autism advocate, does have a high IQ and Asperger syndrome, and she has extraordinary animal science knowledge and abilities. But high IQ and a diagnosis of Asperger syndrome alone are not synonymous with savant syndrome.
“Savant syndrome is not limited to Asperger children,” says Treffert. “Children with classic and sometimes severe autism can have savant abilities. Perhaps there is a larger proportion in Asperger [syndrome], but it is not exclusive.”
Another category in which people with autism are mistaken as savants is in a condition known as “hyperlexia,” where children start reading very early, usually as toddlers. A three-year-old may read on a sixth-grade level, for example. Treffert says hyperlexia in and of itself is not a sign of autism, even if a child with hyperlexia shows signs of autism or has “autistic-like behaviors,” such as insistence to routine or oversensitivity to sound.
Children with hyperlexia may have fewer signs of autism or even outgrow it as they age. Or, they may be wrongly diagnosed with autism. The child’s advanced reading abilities should be viewed as a plus, because those reading abilities can be a “valuable treatment tool for teaching language and social skills,” Treffert explains. Thus, he says it is important not to diagnose every child who has hyperlexia with autism.
“In some cases, only time will sort out the two,” he notes. “What I am asking [is] that except in classic and obvious cases, a diagnosis [of autism] not be applied prematurely for hyperlexia or delayed speech.”