>>The AFQT is an aptitude test. It does not measure intelligence in any way.<<

Of course it does. It does not measure IQ but it does, in some way, measure intelligence.

Here's the definition of "aptitude test":

"test given to determine a person's capacity for learning or doing any of a number of specified types of work."

The key word there is "learning" which is inherently intelligence driven if it involves training from books and manuals--acquiring knowledge. Learning how to operate a wood chipper is a different thing.

Case in point: I know someone who has a good ear for sound production. He has an aptitude for it even though he's not particularly intelligent. The problem is, without someone to show him how a disc recorder works and to stand by and do tasks for him that he can't do himself even though he knows intuitively what he wants to achieve, he's can't use it because he can't sit down and read the manual. To know if he's a good producer requires that he demonstrate some theoretical knowledge of what he is doing and he cannot. So even if he has a good ear for sound, who would hire him? Nobody. At best, he can rise no higher than a studio assistant.

>>As a former field artillery commander, I doubt that I'd have put a CAT-IV (or one of the CAT-Vs we had in the military in the mid-1970s) in the fire direction center, but they did fine in the ammunition resupply platoon. On the other hand, working in the data center is a better job for a higher scoring person than humping projectiles.<<

They can be taught simple activities and maybe more complex ones, but you just can't depend on them for that. But, sure, you can use them for grunt work. Better than wasting someone smart. They can learn a physical activity--they can have a high aptitude for that--but that is no guarantee they can pass an aptitude test. For example, he could be the best ammo humper you ever saw, but if he's functionally illiterate, he can't answer even the simplest questions on a test. So the test inherently takes intelligence into account.