This is hidden brain.
I'm Shankar Vedantam.
All of us know what prejudice looks like.
We've seen news stories about swastikas spray painted on synagogues or nooses drawn on classroom walls to terrorize black students.
We have heard xenophobic speeches from politicians and watched in horror as ethnic groups around the world have exterminated their enemies.
In the late 1990s, Harvard psychologist Mahzarin Banaji and her former PhD advisor Tony Greenwald of the University of Washington, developed a test of hidden bias called the Implicit association test, or IAT.
Unlike the very public spectacle of a burning cross on someone's front lawn, the picture of bias painted by this test was rather subtle.
By measuring the speed of people's associations, the tests show that large numbers of Americans found it easier to associate white faces with positive concepts than to associate black faces with positive concepts.
Many people were similarly quick to associate men with professional activities and slow to associate women with such activities.
Lots and lots of Americans appear to have negative associations about the elderly, the overweight, and the disabled.
Crucially, large numbers of the people taking the tests didn't think of themselves as being prejudiced.
Many prided themselves on having egalitarian beliefs.
Their test results often came as a shock.
The feeling was a feeling of dread, I would say a feeling of having had the rug pulled out from under you.
You have to start from scratch to now rebuild a view of yourself that will forever be a different view of yourself.
In part one of the story, which I strongly recommend you listen to before you listen to this episode, we explore the origins of the psychological test.
Today on the show, we explore what it means that so many people have subtle biases when it comes to their mental associations.
Are these biases benign and just inside people's heads, or do they cause people to act in biased ways?
Is there anything we can do to fight our biases?
The surprising connection between our biases and our behavior this week on hidden brain in George Orwell's dystopian novel, 1984, there were lots of ways to get in trouble with a totalitarian state.