The paper presents the results of an experiment in which a number of high school students with Danish and Muslim names were recruited to put letters in envelopes, paid on a piecework basis. They were to work in pairs, and could choose to work with a person of the same or a different ethnic origin as their own. They could earn more if they worked together with a person of a different ethnic background. How many would elect to discriminate according to ethnicity in such a situation?