Study: NFL Referees Influenced By Coaches' And Players' Sideline Yelling A new study shows 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.

Study: NFL Referees Influenced By Coaches' And Players' Sideline Yelling

Study: NFL Referees Influenced By Coaches' And Players' Sideline Yelling

  • Download
  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

A new study shows 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.


Pro football is well underway, which means you too have a chance to complain about what you see as bad calls by the referees. Now, yelling at your television doesn't make much difference in the world, but it turns out a different kind of yelling may in fact influence the referees. We're going to talk about this with NPR's social science correspondent, Shankar Vedantam.

Hi, Shankar.


INSKEEP: How's this work?

VEDANTAM: Well, it turns out that referees are vulnerable to yelling and screaming from coaches and players standing on the sidelines, Steve. For people who aren't sports fans, opposing teams line up on opposite sides of the field, usually around midfield. I was talking to Michael Lopez. He's a statistician at Skidmore College in New York. He told me he used to coach high school football, and one time, his team scored a defensive touchdown. Now, the touchdown rested in a call the referees had to make on the play. And as it turned out, the action was taking place close to the sideline of the opposing team. Here's Lopez.

MICHAEL LOPEZ: The referees huddled up right in front of the opposing coaches. And so as they're making the decision, you have five screaming high school coaches telling the referees what their opinion was. And meanwhile, on the other sideline, we're sort of sitting there with our hands in our pockets not able to do anything.

INSKEEP: So what happened? Were the referees influenced by the coaches screaming right there beside them?

VEDANTAM: Lopez thinks it was because the call went against his team, but it got him wondering why the psychological pressure from the sidelines could influence the behavior of referees. He's recently analyzed five years of NFL games, more than 82,000 plays, 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.


VEDANTAM: Now, quite often you have bodies flying into one another near a side line. The referee has to make a judgment call. All of this is happening very, very fast.

LOPEZ: That late hit is much easier to call when there's a lot of players and coaches that are standing around screaming that there should be a late hit.

VEDANTAM: So Lopez, Steve, 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 finds referees are much more likely to make calls that comply with what people nearest to them are demanding.

INSKEEP: If the action is on that side of the field, it goes in favor of that team's bench basically.

VEDANTAM: Precisely. Now, pressure doesn't work every time, but it clearly does work.

INSKEEP: OK. So I'm trying to figure out why it works. So the referee's physically intimidated. Is it just the power of suggestion because you're making a snap judgment and somebody is telling you what to think?

VEDANTAM: That's right. You're having to make a judgment call. It's happening very, very quickly, and you have five people yelling at you that you have to make the decision one way. Now, you're not always going to be persuaded, but you're going to be persuaded regularly. That's what Lopez is finding. Now, I asked Lopez, of course, the $64 million question, which is how sports fans like I could actually use this information to help our teams.

INSKEEP: (Laughter).

VEDANTAM: Here's what he said.

LOPEZ: It's hard for me to think that I want teams to take advantage of this because I look at this as more of a human bias that referees are showing that I think is sort of part of a larger picture of what a lot of people would do if we were also in their shoes.

VEDANTAM: OK, so that's a completely unsatisfying answer, Steve. Let me tell you what the implications of the study are.

INSKEEP: Bad call - it's a bad call, Shankar. I want a different call. Call it differently. Call it differently.

VEDANTAM: (Laughter).

INSKEEP: Oh, I'm sorry. Please go ahead with what you intended to say.

VEDANTAM: You got it exactly, Steve. Intimidation works. And teams on the sidelines should yell at referees.

INSKEEP: Shankar, thanks very much for coming by.

VEDANTAM: Thank you, Steve.

INSKEEP: We'll treat you more politely next time. That's NPR's Shankar Vedantam, our social science correspondent, also the host of a podcast that explores the unseen patterns in human behavior, Hidden Brain.

Copyright © 2016 NPR. All rights reserved. Visit our website terms of use and permissions pages at for further information.

NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.