This is most likely a copy from "The Bell Curve" and has been ripped apart more times than one can count. Is this where you hang your hat? Must we do this again? Edit, you should know I have read this book cover to cover and would advise you to stand down. However if you insist, then our good readers here can read the necessary documents in short order. See you soon.
I don't know the exact origins of the pic,it just represents the facts available in the literature. State explicitly what you think you are going to debunk. btw: again? All you have done is bluster and run away. Please link to whence you refer.
If you have enough intelligence to use Google, you'll find this curve to fit many of the IQ studies. <img src="http://lagriffedulion.f2s.com/retar0%7Bimage0%7D.gif">
Am I the only one who sees the gigantic difference between this bell curve distribution, and the one on the previous page? Just noting, regardless of the reasoning for the difference. As far as geography and areas of IQ, would not the Northeast and the Northern Calif area score much higher than, say, the deep South? Does that prove anything like the folks in the South aren't quite as smart. And, yes, I did throw something out here. Let's see what we get back. Will it be the predictable nonsense or something of value?
The verticle scale on this chart appears to be scaled in relative population. The vertical scale on the other chart seems to be using a total population scale. Surely, even you can make that deduction, mrbill.