Overconfidence

Dominic Johnson and James Fowler have created a model to explain the evolutionary underpinnings of overconfidence:

By creating a mathematical model of the way overconfident individuals compete against ordinary individuals, they show that there is a clear advantage in overconfidence.

In fact, if the potential reward is at least twice as great as the cost of competing, then overconfidence is the best strategy. In fact, overconfidence is actually advantageous on average, because it boosts ambition, resolve, morale, and persistence. In other words, overconfidence is the best way to maximize benefits over costs when risks are uncertain.

...

But it is Johnson and Fowler's predictions that are most worrying. Their model implies that optimal overconfidence increases with the magnitude of uncertainty. So the greater the risk, the more overconfident individuals should become.