Holy smokes! What if this is related to the Flynn Effect? Curious.
I am working on some slow-moving research pinning atmospheric lead to AFQT scores, with the hook that the National Guard may act as a sort of third option for intellectual eccentricity.
Need the data still. I asked someone who has already done some leg work, but I've not heard back. I think I may have to do my own FOIA request from the, well, I forget the acronym, but it's the good folks who monitor air quality on behalf of Congress.