If you were on a selection committee tasked with choosing someone to hire (or to admit to your university, or to receive a prize in your field), and it came down to two candidates who were equally qualified on objective measures, which candidate would you be most likely to choose?

__A) The one who shared your race
__B) The one who shared your gender
__C) The one who shared your religion
__D) The one who shared your political party or ideology

The correct answer, for most Americans, is now D. It is surely good news that prejudice based on race, gender, and religion are way down in recent decades. But it is very bad news—for America, for the world, and for science—that cross-partisan hostility is way up.

My nomination for “news that will stay news” is a paper by political scientists Shanto Iyengar and Sean Westwood, titled “Fear and Loathing Across Party Lines: New Evidence on Group Polarization.” Iyengar and Westwood report four studies (all using nationally representative samples) in which they gave Americans various ways to reveal both cross-partisan and cross-racial prejudice, and in all cases cross-partisan prejudice was larger.

First they used a measure of implicit attitudes (the Implicit Association Test), which measures how quickly and easily people can pair words that are emotionally good versus bad with words and images associated with Blacks vs. Whites. They also ran a new version of the test that swapped in words and images related to Republicans vs. Democrats, instead of Blacks vs. Whites. The effect sizes for cross-partisan implicit attitudes were much larger than cross-race. If we focus just on White participants who identified with a party, the cross-partisan effect was about 50 percent larger than the cross-race effect. When Americans look at each other or try to listen to each other, their automatic associations are more negative for people from the “other side” than they are for people of a different race.

In another study they had participants read pairs of fabricated resumes of graduating high school seniors and select one to receive a scholarship. Race made a difference—Black and White participants generally preferred to award the scholarship to the student with the stereotypically Black name. But Party made an even bigger difference, and always in a tribal way: 80 percent of the time, partisans selected the candidate whose resume showed that they were on their side, and it made little difference whether their co-partisan had a higher or lower GPA than the cross-partisan candidate.

Read the article “The Science Is in: Liberals Won’t Hire Conservatives — and Vice Versa” on edge.org.