Though Tetlock hasn’t applied his methodology to Obama, the 44th president would seem to be the very model of the complex thinker. Among the complex thinker’s advantages, says Tetlock, is the ability to see quickly the trade-offs among policy options, to update his beliefs after finding evidence that disproves his preconceptions, and to predict probable outcomes with accuracy. Among the disadvantages: The complex thinker can suffer from “analysis paralysis” and confusion; he can be perceived as unprincipled or disloyal to the values that elevated him to power; and he can be seen as too willing to make trade-offs.

One type of thinker isn’t necessarily better or smarter than the other; it depends on the circumstances. A simple thinker such as Winston Churchill, for example, was a better answer to Adolf Hitler than the complex Neville Chamberlain. “Leaders need to be simple enough for people to relate to,” said Tetlock, “but complex enough to explain to people that they can’t have everything.” Obama was simple enough during his campaign, but, as president, became submerged in subtlety.