[Zanni]

Sorry, forgot my audience. :) STEM folks tend not to be slackers (in their subject). Caplan also mentions this is where most of the measurable learning takes place. And there are non-slackers, to greater or lesser degree, in every class. But I saw a lot of them in the required classes ("core" or "diversity"), language classes and business classes. Most slackers self-select out of STEM, except as required.