Yes, but that wasn't the point of my post; I was replying to:

Finding things (such as convolutions in brains or genes) that are indicative of potentially valuable talent is the kind of thing that helps make efficient use of it.

An MRI machine was an example of a device that could detect convolutions ins brains; a DNA sequencer was an example of a device that could detect genes. My point generalized to "it doesn't matter how good you are at testing for <X indicator of a desired trait>, if you don't apply the test." If we look at IQ tests instead, then (again) it doesn't matter how accurately a properly-administered IQ test detects intelligence, if you don't bother properly administering IQ tests to people in cotton fields, sweatshops, or other places where you don't feel like looking because they aren't "under the lamppost", as it were.