In a recent Stanford study, two different groups of participants were asked to think of a number between one and ten.
Then, they were told they would be given five dollars if they gave an even number to the researchers.
Because people tend to think of odd numbers at a much higher rate than even ones, a large percentage of evens is a good indicator of cheating or dishonesty
In one group, about a fifth said they picked an even number. In the other, nearly half.
The only difference? One word. The first group, which cheated much less, was told that the study was examining "cheaters," and the other that it was looking at "cheating."
It's all about the ego and making it personal. The idea of being a "cheater" is much more immediate than the more abstract idea of "cheating." The effect goes both ways. Not only do people try to avoid seeing themselves in a negative light, they will go out of their way to put themselves in a positive light. Another study found that asking people to "be voters" was much more effective than encouraging them to "go vote."
From signs on tip jars to behavioral cues at work, the way things are phrased can be extremely important.
Read more about the research here