Professor Challenges Autism Assumption: A Willamette U. researcher says the notion that autistic children often have low IQs is flawed
Saturday, November 25, 2006
The conventional wisdom that children with autism are often mentally retarded may be wrong, according to research by a Willamette University professor.
Meredyth Goldberg Edelson, trained as a clinical child psychologist, has discovered that decades of literature linking autism with retardation were based on flawed assertions or contained no empirical research at all.
Mental retardation -- as contrasted with the less precise term "mentally disabled" -- is defined by professionals as a disability that occurs before age 18, characterized by an intelligence quotient under 70 and serious limitations in social and adaptive skills.
Goldberg Edelson reviewed 215 studies on autism, dating to 1937, which made 223 claims about the rates of mental retardation in autism. Only 58 of those claims were supported by data, she found, and most researchers stated their results without reporting how they measured intelligence.
Most of the studies that measured intelligence used tests that were inappropriate, Goldberg Edelson found.
"Many times, if the researchers had a child they couldn't test, they just assumed he or she was retarded and assigned a low IQ score," Goldberg Edelson said.
Autism is a developmental disability that causes problems with communications and social interaction. It is characterized by repetitive behavior and devotion to routine. The severity of symptoms varies widely. The cause is suspected to be complicated interactions between environmental and genetic factors that aren't fully understood.
A child's cognitive ability has never been part of the criteria for autism, but it is frequently mentioned as an associated characteristic. A widely used reference book, the "Diagnostic and Statistical Manual of Mental Disorders," says in most cases, autism is accompanied by mild to profound mental retardation. Other current literature says mental retardation accompanies autism in 67 percent to 90 percent of cases.
Goldberg Edelson, a psychology professor, came to autism research through her husband, Stephen M. Edelson, a researcher and author who was studying effective treatments for children with autism. He asked her to check the intelligence of the children in his tests.
Eventually, she tested 293 children and discovered that their IQ frequently was higher than had been determined by prior tests. Goldberg Edelson found that often the children had been given timed tests or tests that required them to follow verbal instructions or give verbal answers, conditions that are frequently hard for autistic children to deal with.
Goldberg Edelson used untimed tests that measured nonverbal intelligence. On average, the children scored a 90 -- near average -- on the IQ scale. Only 19 percent were within the range of mental retardation.
That prompted Edelson to examine the literature on autism.
She found that much of it wasn't legitimate research, and those studies that did assess intelligence were flawed in their methodology. Her results were published recently in Focus on Autism and Other Developmental Disabilities, a scholarly journal on autism.
Bertram Malle, an associate professor of psychology at the University of Oregon, said autism covers a wide spectrum of developmental disorders and some children with autism are highly intelligent.
"It's important for parents of autistic children to understand that there in a huge range of intellectual capacity and behavior," he said. "Some of the behavior is amenable to improvement.
Malle said he's seen cases in his own field, social psychology, in which long-held assertions turn out not to be valid. "Sometimes stereotypical beliefs are held on to," he said. "You make a claim, it's not challenged, and then the claim is repeated to the point that it becomes generally accepted."
Goldberg Edelson said it's clear that the real rate of mental retardation among autistic individuals isn't known. "I think we need to go back to the beginning and find out just what we do and do not know about autism and mental retardation, she siad.
Goldberg Edelson, 45, said she hopes that her research helps prevent therapists and educators from setting artificially low expectations for children with autism.
"In the 1950s, children with autism were institutionalized," she said. "If most children with autism aren't mentally retarded, we need to find ways for them to interact with society and help them become all they can."
Steven Carter: 503-221-8521