Why Luis Suarez Bites People, According to Science

The Beautiful Game's most infamous vampire has drawn blood again: In the tense, winner-take-all Uruguay vs. Italy World Cup match, the universally reviled striker Luis Suarez pretty clearly leaned in and took a bite of Giorgio Chiellini's shoulder. The ref didn't catch it, Uruguay went on to upset the Azzuri, and the postgame buzz is all about whether FIFA will review the incident and ban the star player from the tournament. The bigger question, I think, is, what the hell?

Why bite? It's not like it's a more discreet way to inflict pain on an opponent—if the ref were facing in that general direction, he would have plainly seen Suarez leaning in, mouth agape, and proceeding to gnash Italian flesh like a crazed Twilight superfan. It is an entirely ridiculous, rather inefficient, and fairly revolting way to express athletic frustration.

Yet there's a long, storied history of athletes and brawlers exploiting their incisors; the most famous, obviously, being Mike Tyson's 1997 ear chomp. Rugby players have been known to bite in the midst of scrums, when it is indeed hard for the ref to catch the human feasting. But Suarez is evidently trying to claim the title of most infamous biter in sports—this is at least the third time he has bit an opponent during regulation play, in nearly as many years.

Last year, he was suspended for 10 games for biting Branislav Ivanovic on the arm. In 2010, Suarez was benched for seven games for another bite. He's earned the nickname the 'cannibal' for his toothy antics. (He is also a noted racist, and crushed Ghana's 2010 World Cup hopes with a flagrant intentional handball, in case you were looking for more reasons to hate him).

Luis Suarez may be kind of repulsive, but human-on-human biting isn't actually all that uncommon. A 2007 National Institutes of Health study found that human bites were the third most-treated kind of mammal bites in the emergency room, behind dog and cat bites, accounting for anywhere between 5-20 percent of bite cases. That's a not-insignificant number of human bites.

The study exclusively examined "occlusive bites"—the intentional teeth-on-skin aggression a la Suarez and Tyson—versus "fight bites," which occur when a fist or arm gets punctured when it slams into someone else's mouth.

Men are 12 times as likely to sustain biting injuries, and in nearly 90 percent of the cases—surprise—alcohol was involved, the study found.

You're getting the picture. Men, drunk or jacked up on adrenaline, in a pub or an arena, are prone to turning into sweaty, tweaked out vampires. This still doesn't explains the why, though. It still seems like a pretty pitiful combat option—why did Tyson chow on Hollyfield? Why does Walter bite off the ear of that leather-clad nihilist?

To find out, the BBC interviewed sports psychologist Dr. Thomas Fawcett in the wake of Suarez's 2013 incident. After reviewing the tapes extensively, Fawcett said that the chomp was a "primitive response" in which emotions overrode the rational thought process.

"It's not pre-planned," Fawcett told the BBC, "it's a very spontaneous, emotional response. He's doing it on impulse." That helps explain why a good many human-on-human bites spring from bar fights or aggravated physical circumstances; it's primal and animalistic. And it's a lot more powerful than most people might think.

A study published in the Proceedings of the Royal Society B sought to refute the notion that humans are bad biters, and in fact boast one of the most powerful primate jaws.

"When you actually look at the mechanics of it, the human jaw is highly efficient," Stephen Wroe, the study's author, told Discovery News. "For any given bite force you want, we can achieve it with much less muscle." Our jaw, he claimed, is 40-50 percent more efficient than the great apes. "Pound for pound we're actually biting harder than a gorilla or a chimpanzee." Our bite strength is actually comparable to a nutcracker's, he says.

There are other reasons humans bite humans besides aggression, of course. Odaxelagnia describes the paraphilia related to the sexual arousal derived from biting. There are still some tribes and groups that practice cannibalism, which requires some pretty serious biting. And criminologists have noted that a certain type of violent criminal will bite, not out of aggression, but out of sadistic desire to stigmatize their targets.

"[Biting is carried out] to mark a victim," the criminologist David Wilson told the BBC. "But I think what's more important to the perpetrator is that it reveals something about how they viewed that particular victim."

Suarez, a serial biter, may fall between the criminologist and the psychologist's diagnosis. But we can be fairly certain of at least one thing: even if he's suspended for the full 24 games he's currently facing, Suarez will likely live and play to bite again.

In the wake of his first bite, in 2010, Suarez was offered anger management therapy. Dr. Fawcett said, presciently, that it probably wouldn't help.

"It's in the man," he said. "I would think that in five years' time if there was a certain nerve hit or chord rung with Suarez in a different situation he would react in the same way."