World Cup referees may not care about which team wins, but they do care about the direction in which players are moving. Motion, it turns out, looks more ominous going from right to left than from left to right, at least to people raised reading left-to-right languages. (It's a twisted phenomenon that film directors and comic book artists exploit.) To find out if this phenomenon could bias soccer referees, researchers showed photos of potential fouls to 12 college soccer players. They found that players were 5% more likely to call a foul if the pictured player was moving (or stumbling) to the left rather than to the right. Thanks to the referee's diagonal system of covering the field—from the bottom left corner to the top right—they see right-to-left attacks much more often than they do left-to-right attacks. The partiality tends to favor whichever team is on the offense, the researchers report  online this week in PLoS ONE. That because, in the penalty box, more fouls equal more penalty kicks—and thus more chances to score.
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