There is actually an important reason why the US Military does IQ testing: they tried using low IQ troops in Vietnam; it didn't work very well.
Or, if you were aware that the problems they had in supplying raw manpower to Vietnam led the army to emphasize drafting people who should legally have been unable to serve based on their very low IQs, you could observe that it would be pretty shocking if veterans as a class showed equal earning power to society in general.
> They were, to put it bluntly, mentally deficient. Illiterate. Mostly black and redneck whites, hailing from the mean big city ghettos and the remote Appalachian valleys.
> By drafting them the Pentagon would not have to draft an equal number of middle class and elite college boys whose mothers could and would raise Hell with their representatives in Washington.
> The young men of Project 100,000 couldn't read, so training manual comic books were created for them. They had to be taught to tie their boots. They often failed in boot camp, and were recycled over and over until they finally reached some low standard and were declared trained and ready.
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