From: the Dilbert blog
One of the most potent forms of persuasion has to do with people’s innate need to be consistent. Studies show that people will ignore logic and information to be consistent. (In other words, we are moist robots.) According to the research, humans are hardwired for consistency over reason. You already knew that: People don’t switch political parties or religions easily. What you didn’t know is how quickly and easily a manipulator can lock someone into a position.
For example, researchers asked people to write essays in support of a random point of view they did not hold. Months later, when surveyed, the majority held the opinion they wrote about, regardless of the topic. Once a person commits an opinion to writing – even an opinion he does not hold – it soon becomes his actual opinion. Not every time, but MOST of the time. The people in these experiments weren’t exposed to new information before writing their contrived opinions. All they did was sit down and write an opinion they didn’t actually have, and months later it became their actual opinion. The experiment worked whether the volunteers were writing the pro or the con position on the random topic.