> If you could create some score of peoples intelligence, how they react/respond to people, their normal physical movements and put that into a distribution the autistic people would definitely be on the tail end of the curves.Some measurable aspects of human physiology and behavior would fall into a normal distribution (i.e. "bell curve") if you graph it, yes. Bell curves are common enough that there is a lay assumption that all distributions look like that, but it isn't the case, at all. Certain forces are required to lead to that flavor of distribution and in the absence of those, you can get graphs of all sorts of shapes.
For example, if you were to graph "how feminine" a set of people are, you're unlikely to get a bell curve where most people are androgynous. Instead, you get a bimodal distribution where there's a hump on one side for dudes and one on the right for ladies. In fact, graphs of height show a similar distribution.
If you graph how many fingers someone has, you'll probably get something closer to a power law where almost everyone is on the left at "10", a few misfortunate at "9", even few very unlucky at "8", and so on. (Plus a couple of odd points for polydactyly, etc.) This is the famous "long tail" you hear about in economics.
So there is certainly variation in all attributes, but that does not imply that the center of that range is the most populated. And thus, there may not be a "normal" in the typical "average and most common" sense of the word.
What does a normal set of genitals look like?