There is a natural human tendency to dislike a person who brings us unpleasant information, even when that person did not cause the bad news. - Robert B. Cialdini

First, we seem to assume that if a lot of people are doing the same thing, they must know something we don’t.

we all fool ourselves from time to time in order to keep our thoughts and beliefs consistent with what we have already done or decided.

Social scientists have determined that we accept inner responsibility for a behavior when we think we have chosen to perform it in the absence of strong outside pressures. A large reward is one such external pressure. It may get us to perform a certain action, but it won’t get us to accept inner responsibility for the act. Consequently, we won’t feel committed to it. The same is true of a strong threat; it may motivate immediate compliance, but it is unlikely to produce long-term commitment.