The reality is that there’s still a lot of prejudice in the world today. Public awareness campaigns have used various means to try and turn it around, but according to a new study, depending on the tactics they use, they may be doing more harm than good.

To test how effective various methods are, researchers gave participants two different types of brochures. One used a “controlling” method of motivation, telling people that they should be more accepting to “comply with societal norms of nonprejudice.”

A more effective way seems to be to encourage people to make their own decisions about how to act, by explaining the benefits and costs as neutrally as possible. Legault adds that “people need to feel that they are freely choosing to be nonprejudiced, rather than having it forced upon them.”

The other type of pamphlet used a different tack, focusing more on personal motivation: it explained why one should be accepting, and how it can be “important and worthwhile.” A third group of participants received no pamphlet at all.

Interestingly, the team found in follow-up tests that people who had been giving the “controlling” pamphlet showed more racial prejudice than people who had received no information at all. The people who’d read the brochures promoting nonprejudice for more personal reasons had the least prejudice of all three groups.

A second experiment “primed” people by using a questionnaire that was designed to encourage either controlling or personal motivation. Again, the researchers found that people were more racially prejudiced when they had received a message of controlling motivation.

The results of the study may seem ironic, since telling people not to do something should theoretically work. But people don’t like being told what to do. And being instructed to think or behave in a particular manner clearly does not go over well.

“Controlling prejudice reduction practices are tempting because they are quick and easy to implement, said Lisa Legault in a university news release. “They tell people how they should think and behave and stress the negative consequences of failing to think and behave in desirable ways.”

A more effective way seems to be to encourage people to make their own decisions about how to act, by explaining the benefits and costs as neutrally as possible. Legault adds that “people need to feel that they are freely choosing to be nonprejudiced, rather than having it forced upon them.” Hopefully the writers of public awareness campaigns will take the findings into account as they design new techniques to encourage nonprejudice.

The study was carried out the University of Toronto Scarborough and will be published in an upcoming issue of Psychological Science.