In 2011, Anya C. Savikhin of the University of Chicago had classes of preschool children compete with each other to win candy. Savikhin’s research team matched children up into competing pairs. In separate rooms, each preschooler in the pair attempted to catch as many toy fish as possible using a magnetic pole. The more successful fisherman moved on to the next round in a tournament, chasing the promise of a candy windfall.

Savikhin designed the experiment to study the competitiveness of young boys and girls with an eye toward how gender differences in competitiveness may affect educational outcomes.

But she discovered something else of interest during the experiment. When the children were asked if they thought they had beaten their opponent - who they had not seen play - over 80% believed that they had. Yet only half of them could have possibly beaten their opponent. In other words, the Chicago preschoolers were seriously overconfident in their toy fishing abilities.

It may seem like just a funny quirk that these children assumed that they were better at a new game than the other kids. But it actually captures an interesting psychological puzzle. In a statistical impossibility, over 50% of adults consistently report that they are above average. Almost all drivers think they are better than the average driver. Ninety four percent of college professors believe that their teaching skills are above average. A survey of high-school students found that 70% described themselves as above average leaders. Is everyone engaged in egotistical self deception?

The problem with answering that question is that - like the preschoolers who have never seen any of the other players - everyone is answering the question with incomplete information. We haven’t seen every other driver, college professor, and high school soccer captain. Maybe we assume that we’re better drivers because terrible drivers on the road are so memorable and good drivers so forgettable. Or maybe, in light of the difficulty of knowing the truth, we just want to show a little optimism. Perhaps we lie because confident people are viewed more positively, because we believe in the power of positive thinking, or (as some academics have proposed) because overconfidence gave our ancestors an evolutionary edge in fights for mates and resources where the outcome was not clear.

We have not seen a definitive answer, but some research claims to narrow down the list of possible explanations.

One explanation given is that evidence of this overconfidence effect has been observed in the United States in Europe - and Westerners are an unusually individualistic and egotistical bunch. Some researchers testing for the effect in more “collectivist” cultures like Japan found that the effect disappears, while others did not. What gives?

The answer proposed by two psychologists - one American, one Japanese - is that since, in general terms, these other cultures wrap up social relationships into their sense of self-worth, asking only about them as individuals misses out on what they consider important. When they asked Japanese students about friends and family members, they found that students rated them as above average in comparison to others - a finding replicated in other non-Western cultures.

Like many of the explanations though, this begs the question of whether people really believe (or thought realistically) about their answers. After all, how many people do you expect to rate their mothers below average?

One study sought to investigate by having participants perform a personality test. The participants then predicted how they fared compared to the rest of the group, after which they made a series of bets based on their rank. Once again, people brimmed with confidence, expecting that they rated higher than their peers in traits like intelligence. But when money was on the line, they stood by their overconfident predictions. The results can only prove so much (after all, the academics only had enough funds to make the bets worth a few dollars), but it is evidence that people really believe that they are above average.

Whatever the explanation, we’re living in a statistically impossible world in which every parent is right that their child is special, talented, and most of all, above-average.

This post was written by Alex Mayyasi. Follow him on Twitter here or Google Plus. To get occasional notifications when we write blog posts, sign up for our email list.