Rose Eveleth writes at Scientific American:
Researchers have long considered the majority of those affected by autism to be mentally retarded. Although the numbers cited vary, they generally fall between 70 to 80 percent of the affected population. But when Meredyth Edelson, a researcher at Willamette University, went looking for the source of those statistics, she was surprised that she could not find anything conclusive. Many of the conclusions were based on intelligence tests that tend to overestimate disability in autistic people. "Our knowledge is based on pretty bad data," she says.
This hidden potential was recently acknowledged by Laurent Mottron, a psychologist at the University of Montreal. In an article in the November 3 issue of Nature, he recounts his own experience working with high-functioning autistic people in his lab, which showed him the power of the autistic brain rather than its limitations. Mottron concludes that perhaps autism is not really a disease at all—that it is perhaps just a different way of looking at the world that should be celebrated rather than viewed as pathology.