Apparently, 94% of university professors believe they are better at their job than their colleagues.

Most people think they are better than average. You probably do, too. And by definition, that must mean that most people think they are better than most. The question is, does it matter? Is self-deception a good or bad thing in the workplace?

Quattrone and Tversky conducted a classic social psychology experiment to study self-deception. As is often the case in such experiments, the researchers lied to the participants about every aspect of the study.

Firstly, they told them the study was about the "psychological and medical aspects of athletics". Then they tricked them into believing that a measure of good health could be gauged by the length of time you could submerge your arms in very cold water.

Naturally, this was nonsense. All it showed was how ready they were to deceive themselves and what they would do for £50. Typically most people could endure the cold water for 30 seconds. To make participants believe the study was real they were given other tasks to do as well. Walking over hot coals with no shoes on wasn't one but it would have made an interesting footnote. Instead, they did a stint on an exercise bike.

Crucially, they were then given a short lecture about how life expectancy depended on your type of heart. Lying through their teeth, and presumably just managing to suppress a giggle, the researchers revealed that there were two types of heart: one associated with poor health and one associated with top-class athletes.

Continuing with the porkies, the researchers then said it was possible to tell which type of heart you had by measuring your tolerance to cold water after exercise. But here's the rub. One half were told an increased tolerance to cold water indicated a strong heart, while the other half were told it was a decreased tolerance to cold water.

You can probably guess the outcome. Everybody deceived themselves into believing that they had an athlete's heart by either enduring the cold water for less or more time than previously depending upon the lie they were told.

One man was determined to deceive himself so much he submerged his whole head into the water for three minutes and then called for the hot coals 'for good measure' as he was led away to the ambulance. Or did I just make that up?

No matter. What this study suggests is that for many people self-deception is easy. So if you manage people why not tell them they are very, very good indeed? Because the more they believe, the better they'll be.

Philip Hesketh is a professional speaker on the psychology of persuasion and author of Life's A Game So Fix the Odds.

Topics