Nobody really knows what causes exist. I'm of the OPINION there could be many different factors in every Autistic case.
Among them I think are:
Physical environmental factors (pollution of various kinds, including noise pollution)
Emotional environmental factors (stress caused by a number of possible things ~ such as, but not limited to, family members that suffer from emotional disorders ~ I don't mean genetic, I mean just the fallout from being exposed to it ~ abuse - both emotional and physical)
Genetic factors
Cultural factors (i.e. attitudes and paradigms handed down through many generations)
I highly doubt any one cause will ever be found. I think it's multiple factors that may or may not someday be identified.
I'm totally satisfied vaccines have nothing whatever to do with it.
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I'm not likely to be around much longer. As before when I first signed up here years ago, I'm finding that after a long hiatus, and after only a few days back on here, I'm spending way too much time here again already. So I'm requesting my account be locked, banned or whatever. It's just time. Until then, well, I dunno...