Football referees are unbiased, right? They would never be influenced by fans or football players, right? Well, according to a recent study football refs are often swayed by their surroundings. Michael Lopez, a researcher and statistician at Skidmore College in New York, led a study that referees are much more likely to make calls that favor the team whose coaches and players are on the sideline closest to the potential penalty.

Lopez analyzed five years of NFL games, including 1,400 penalty calls where the action happened close to one team's sideline or the other. One of the files he examined was whether referees called a late hit on a player. If one player is tackling another, you're allowed to do it while the opposing player is within bounds but not if he's out of bounds. But the bodies are usually flying into one another near a sideline. It's what's called a bang-bang play: it all happens so quickly and the refs have to make a judgment call.

Lopez measured how often these kinds of judgment calls go in favor of the team whose coaches are on the sideline closest to where the potential penalty is taking place. He found referees are much more likely to make calls that comply with what people nearest to them are demanding. In short, intimidation works. Pressure the refs, get in their face, and they will often cave into social pressure.