These are all caricatures, not characterizations. They work well enough for cardboard background characters. The professor, the dorky date, whatever. But what about the real challenge: the smart major character? Nobody wants to spend three hundred pages with someone who mutters about Wittgenstein and wears a tweed coat. We can't all be Bertrand Russell. You see what I did there.
Here's my favorite trick, because not only is it a little-known trait of the very smart person, it also creates conflict when they try to deal with the rest of us:
Taking the Long View.
Basically, the smarter the person, the broader the time frame they consider when making decisions. We can see this in operation now, with the federal budget debate happening here in the US. Economist Paul Krugman used the phrase "Eat the Future" in the New York Times this weekend, referring to the GOP's efforts to slash budget items that won't cause pain today but will cause enormous pain tomorrow. As Krugman puts it: "Focus the cuts on programs whose benefits aren’t immediate; basically, eat America’s seed corn."
I won't call the GOP a bunch of morons. But House members are running for reelection at all times, and they want to lower the deficit without causing their current voters any pain. Who cares what collapses in thirty years? They meet conflict from folks who want to, for instance, cancel some of the pork forever flying at the Department of Defense (like Secretary of Defense Gates). No, those are jobs! Means test other entitlement programs? No, those are voters! Wait those thirty years; we'll be retired and our voters will be dead.
Here's who won't get elected to the US House of Representatives: Oren Lyons, the Chief of the Onondaga Nations. That gentleman, and his Council, are bound to The Great Binding Law of the Iroquois (from Wikipedia):
"In all of your deliberations in the Confederate Council, in your efforts at law making, in all your official acts, self interest shall be cast into oblivion. Cast not over your shoulder behind you the warnings of the nephews and nieces should they chide you for any error or wrong you may do, but return to the way of the Great Law which is just and right. Look and listen for the welfare of the whole people and have always in view not only the present but also the coming generations, even those whose faces are yet beneath the surface of the ground – the unborn of the future Nation."
This is also known as seven generations sustainability, and says that any decision undertaken by the Council had to consider the ramifications for seven generations into the future. Obviously, this sort of thinking would get the poor US House member run out on his or her ear.
Imagine a character who looks ahead. Who considers consequences. Who saves against bad times. Who invests. Who plants trees. Who can see a path into the future for a company, a family, a relationship. Who can see trends in science, in art, in history. There is a genius.
Now imagine how well-understood that person will be. Imagine how well liked. Right, not at all. Write the smart character. Use the smart character. And remember in life that the old saying "a stitch in time saves nine" is true. Take the pain now. We can pass on far worse than a deficit if we're not careful. If we're not smart.
As they say in medicine, "All bleeding stops. One way or the other."