Although researchers have not found cultural variability in phenotypic expression of ASDs, cultural variables may affect prevalence estimates. Indications generally suggest ascertainment bias toward lower prevalence in South Korea since Koreans consider autism to be a stigmatizing hereditary disorder; autism (chap'ae) impugns the child's lineage on both sides and threatens the marriage prospects of unaffected relatives. As a result, autism is often untreated, misdiagnosed as attachment disorder, or unreported in records. Although our total population approach avoided clinical and administrative obstacles associated with stigma, it is possible that some parents, fearing a diagnosis, chose not to report ASD symptoms or to participate in diagnostic evaluations.
I don't know if this blog has any Korean readers --- if any of you are reading, I'd love to hear your thoughts on the accuracy of the quoted passage.
Taking the passage at face value, it seems to me that the difference in stigma associated with autism in the U.S. and in Korea is more a matter of where the stigma is directed than whether a stigma exists at all. Autism is very much a stigmatized condition here; it's just that the family members aren't seen as tainted with faulty genetics (and thus less marriageable) as much as they are alternately pitied and lionized for living with an autistic person. The stigma here is directed almost entirely at the autistic person hirself, although of course parents and caregivers who make choices that don't fit with the current ideas of what's best for an autistic child come in for some serious disapproval, too.