The popular image of scientists is of a tiny, elite (and possibly deranged) minority of people engaged in esoteric pursuits. One of the three most common responses when I tell somebody I’m a physicist is, “You must be really smart. I could never do that.” (The other responses are, “I hated that when I took it in high school/college,” and, “Can you explain string theory to me?” This goes a long way toward explaining why physicists have a reputation as lousy conversationalists.)
While the idea that scientists are uniquely smart and capable is flattering to the vanity of nerds like me, it’s a compliment with an edge. There’s a distracting effect to being called “really smart” in this sense — it sets scientists off as people who think in a way that’s qualitatively different from “normal” people. We’re set off even from other highly educated academics — my faculty colleagues in arts, literature, and social science don’t hear that same “You must be really smart” despite the fact that they’ve generally spent at least as much time acquiring academic credentials as I have. The sort of scholarship they do is seen as just an extension of normal activities, whereas science is seen as alien and incomprehensible.