Daniel Engber looks at why we root for them:

[It] may be smarter to gamble your emotions on the team that's most likely to reward you with a stirring victoryand that's least likely to crush your soul. For Frazier and Snyder, that means betting on the underdog: If they win, it's the greatest feeling in the world. And if they losewell, you kind of knew that would happen all along. The same reasoning applies in reverse: If you're pulling for the favorite, then a loss cuts extra deep, while a victory merely delivers what you thought you deserved. "Thus a utilitarian model would indeed predict the underdog effect," the authors observe.

In response, Jonah Lehrer points out that refs are immune to this effect and instead tend to favor the home team:

[W]hile the rest of us are rooting for the underdog, the referees are just trying not to get booed. And since the underdogs rarely have home-field advantage, the data suggests that refs and umps actively counter our desire for underdog victories. They make the superstars more likely to win.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.