Strong reactions to touch are remarkably widespread among people who have autism, despite the condition’s famed heterogeneity. “The touch thing is as close to universal as they come,” says [autistic blogger] Gavin Bollard.
The common thread may be an altered perception of ‘affective touch,’ a sense discovered in people only a few decades ago. ‘Discriminative touch’ tells us when something impinges on our skin, with what force and where; affective touch, by contrast, conveys nuanced social and emotional information. The kinds of touch that autistic people may find loathsome, such as a soft caress, are associated with this latter system.
A growing number of studies indicate that affective touch is at least partly responsible for our ability to develop a concept of self, something long thought to differ in people with autism. Even newer is the idea that an atypical sense of affective touch may be one of autism’s underlying causes.
“Maybe this is actually getting at a biological marker that gets us a better understanding of the causes of autism and, at the very least, a very early detection of autism,” says [neuroscientist] Kevin Pelphrey.
Read full, original post: How ‘social touch’ shapes autism traits