Not sure I explained it very well but for anyone who hasn't read the book, there is a theory that children who were said to have been snatched by fairies and replaced by an imposter child actually had SN and their parents/society were trying to explain their differences however they could.
Similarly children raised by wild animals were not how they were because of being raised without human contact but they were abandoned because parents could not cope with them. I studied child development and they used these rare cases of children recovered from the wild as proof of how important human interaction was. I remember wondering how the heck you accidently lose a baby and it crawls off to join a wolf pack.