That tension forms the backbone of so much dystopian sci-fi: The protagonist of Divergent is special because she doesn't fit into her society's rigid castes of personality traits; Minority Report is all about the follies of judging people before they act. These stories are fun to think about in part because they're fiction, not fact.

But now that neuroscientists have used maps of people's brains to accurately predict intelligence, reality creeps ever so much closer to fiction.

By intelligence, in this case, the scientists mean abstract reasoning ability, which they inferred by mapping and analyzing the connections within people's brains. But the study, published today in Nature Neuroscience, is compelling because it gets at a fundamental and very uncomfortable truth: Some brains are better than others at certain things, simply because of the way they're wired. And now, scientists are closer to being able to determine precisely which brains those are, and how they got that way.