If we reverse the logic, though, it's a bit more obvious: Those who quit don't make it through ;-) But the question is, are they actually selecting the best ca

If we reverse the logic, though, it's a bit more obvious: Those who quit don't make it through ;-) But the question is, are they actually selecting the best candidates by using that criteria (ability to persevere)? In the case of the SAS it may very well be true, but possibly it's a special case.