Autism rate closer to 2.6%

As reported by the NY Times, the finding of a 6 year study on the prevalence of autism done in a small town in South Korea found that the autism rates in the general population are closer to 2.6% than the previously supposed 1%. More interesting than the findings is the methodology and its implications for a similar study on sociopathy in the near future:

For the study, which is being published in The American Journal of Psychiatry, researchers from the Yale Child Study Center, George Washington University and other leading institutions sought to screen every child aged 7 to 12 in Ilsan, a community of 488,590, about the size of Staten Island.

By contrast, the Centers for Disease Control and Prevention in the United States and most other research groups measure autism prevalence by examining and verifying records of existing cases kept by health care and special education agencies. That approach may leave out many children whose parents and schools have never sought a diagnosis.

In recent years scientists have come to see autism as a spectrum of disorders that can include profound social disconnection and mental retardation, but also milder forms, like Asperger’s syndrome, that are pervasive and potentially disabling but that often go undiagnosed.

“From the get-go we had the feeling that we would find a higher prevalence than other studies because we were looking at an understudied population: children in regular schools.”

I wonder what would happen if a similar study for sociopathy was done on a small town. The autism study found larger than expected numbers among "the poor, among racial minorities and “potentially among girls.” Here's what they found amongst the hidden majority:

Among the children with autism spectrum disorder in regular schools, only 16 percent were intellectually disabled, more than two-thirds had a milder form of autism, and the ratio of boys to girls was unusually low: 2.5 to 1. In addition, 12 percent of these children had a superior I.Q. — a higher proportion than found in the general population.

Three guesses at where larger than expected numbers for sociopathy would come from and what unexpected traits they might find in a higher proportion to the general population. And would there be any opposition to testing children for sociopathy this way?