Why are soccer referees biased at times?

WASHINGTON - Soccer referees may have an unconscious bias towards calling fouls when action moves right to left or leftward.

So say researchers from the University of Pennsylvania School of Medicine in the US.

The finding suggests that two referees watching the same play from different vantage points may be inclined to make a different call, says a study published in the on8line edition of Public Library of Science ONE.

It has been documented that individuals who read languages which flow left-to-right are more likely to have a negative bias for events moving in the opposite direction, says a University of Pennsylvania release.

In the Pennsylvania study of members of its soccer teams, researchers found that participants viewing the soccer games were more likely to call a foul when seeing a right-to-left attack.

“The effects are impressive considering that left-moving and right-moving images were identical, the only difference being they were flipped along the x-axis,” said Alexander Kranjec, a post-doctoral fellow in neurology at the University of Pennsylvania School of Medicine who led the study.