Think all Republicans are anti-science or religious people are stupid?  You may look for data to rationalize your bias but a new study in Psychological Science says it may just be your own low self-esteem; when people are feeling badly about themselves, they're more likely to show bias against people who are different from them. 

Jeffrey Sherman of the University of California, Davis, who wrote the study with Thomas Allen, used the Implicit Association Test (IAT), a task designed to assess people's automatic reactions to words and/or images, to investigate this claim.

In their study they sought to reveal people's implicit racial prejudice so participants were asked to watch a computer monitor while a series of positive words, negative words, and pictures of black or white faces. In the first part of the test, participants are asked to push the "E" key for either black faces or negative words and the "I" key for white faces or positive words. For the second task, the groupings are reversed and participants were supposed to associate positive words with black faces and negative words with white faces. 

Determining prejudice in the IAT is pretty straightforward: If participants have negative associations with black people, they should find the second task more difficult. This should be especially true when people feel bad about themselves.

But what psychologists don't agree on is how this works. "People were using the exact same data to make completely different arguments about why," Sherman says. There are two possibilities: either feeling bad about yourself activates negative evaluations of others, or it makes you less likely to suppress those biases.

In their experiment, Sherman and Allen asked participants to take a 12-question test that requires creative thinking. No one got more than two items correct. About half of the participants were given their test results and told that the average score was nine, to make them would feel bad about themselves. The other half were told that their tests would be graded later. All of the participants then completed the IAT and, as expected, those who were feeling bad about their test performance showed more evidence of implicit prejudice. 

Sherman and Allen took it a step farther. They also applied a mathematical model that reveals the processes that contribute to this effect. By plugging in the data from the experiment, they were able to determine that people who feel bad about themselves show enhanced prejudice because negative associations are activated to a greater degree, but not because they are less likely to suppress those feelings. 

The difference is subtle, but important, Sherman says. "If the problem was that people were having trouble inhibiting bias, you might try to train people to exert better control," he says. But his results suggest that's not the issue. "The issue is that our mind wanders to more negative aspects of other groups. The way around that is to try and think differently about other people. When you feel bad about yourself and catch yourself thinking negatively about other groups, remind yourself, 'I may be feeling this way because I just failed a test or something.'"