Overconfidence is the human norm

Humans have evolved to develop an over-inflated sense of our own abilities, which ultimately helps us to survive against the odds, scientists have discovered.

It sounds counter-intuitive that a penchant towards over-confidence should be biologically beneficial, but by crafting a mathematical model in which notional "players" compete for limited resources and decide whether to fight or back down based on an assessement of their opponent's apparent strengths, researchers James Fowler from UCSD and Edinburgh University scientist Dominic Johnson have shown that the best strategy is to err on the bullish side.

In other words, the costs of walking away from conflicts you might win are outweighed by the potential gains that come with taking a gamble if the prizes are sufficiently large. This over-egging of human self-belief might explain a lot about our behaviour, such as financial bubbles, wars we cannot win, tendencies to smoke or drive dangerously and even, Johnson points out, complacency about climate change.

Published in the journal Nature, the study also goes some way to explaining why a staggering 94% of University lecturers, when asked, rate their teaching skills as "above average". In fact, the only people who appear to have an accurate view of the world are those suffering from depression who display what's known as "depressive realism". And judging by their experiences, the advantages of pepping up our personal attributes are clear.

"It's this unrealistic view of the world is what gets us through life," says Johnson.