In this experiment, researchers asked college students whether they would be willing to walk around campus for 30 minutes wearing a large sandwich board bearing the message: "Eat at Joe's."

The researchers then asked the students to estimate how many other people would agree to wear the advertisement. They found that those who agreed to carry the sign believed that the majority of people would also agree to carry the sign. Those who refused felt that the majority of people would refuse as well. So whether they agreed to promote "Joe's" or not, participants were strong in their belief that most others would have made the same choice.

The results demonstrate what is known in psychology as the false consensus effect. No matter what our beliefs, options, or behaviours, we tend to believe that the majority of other people agree with us and act the same way we do.