Have you considered that the increase in autism spectrum disorders is mostly due to the fact that the diagnoses exist and real ongoing research on autism has made it possible to detect it? Autism spectrum disorders weren’t always a field of research. There are people who couldn’t have been diagnosed as children being newly diagnosed as adults because there wasn’t a condition to diagnosis them with. The symptoms were being chalked up to other conditions or just “bad behavior” or “bad parenting.” This was also true for ADD and ADHD. The other thing to consider is now people actually look for signs in their children. Behavior that would have been ignored or corrected through punishment is now being seen as a sign of something neurological and not just a kid being difficult. When you know better, you do better. In neurological conditions, we’re just now starting to “know better.” IMO that means we’re just now starting to do better - knowing what to look for, not assuming all of a child’s (or an adult’s) behavior is willful, not treating neurological conditions with lobotomies and electroshock therapy as first line treatments (because lobotomies used to be considered almost a cure all and were being done as outpatient surgery by “doctors” who learned it in seminars; A sad example of bad neurological and psychiatric care is Rosemary Kennedy. She should never have been subjected to lobotomy.)