Many years ago now a professor at Berkley ran a study about racism. He would have students of different racial backgrounds answer a test. They were told it was to determine what race was racist. The students THOUGHT it was to get their impressions of others. Instead, it was meant to score their own racism.
One example the professor gave: There were two questions on the questionare. One was at the first and one close to the end. The first question was: "If you enter a restaurant and a [pick a race] person meets your eyes, is he racist?" The second question was: "If you enter a restaurant and a [pick a race] person does not meet your eyes, is he racist?"