What’s the News: We may strive for humility, but we benefit from a little hubris, too, according to a study published last week in Nature. Overconfidence in your abilities can help you triumph in competitions you might not have won otherwise, the study found, and can impart an evolutionary advantage when the potential payoff is high compared to the cost of conflict.

How the Heck:

• To investigate the effects of overconfidence, the researchers set up a game theory-based computer model. In this model, two individuals could each “decide” (through computer algorithms) whether or not to lay claim to a desired resource. If they both claimed it, the stronger individual won the resource, but both individuals incurred a small cost, the toll of competition. If only one individual decided to go after the resource, that individual got the prize without incurring a cost from conflict; if neither did, neither got it.
• Each competitor decided whether or not to claim the resource based on what they knew of their abilities compared to their opponents’. But, as is usually the case in real life, the individuals didn’t have a complete, unbiased view of the situation: The model varied whether each individual was overconfident or underconfident in their own abilities, and how uncertain they were about their competitors’ abilities.
• The computer simulation went through thousands of generations of these competitions. To mimic natural selection, strategies with high fitness—meaning they resulted in more rewards, fewer costs—were passed down to the next generation.
• The researchers found that being overconfident in one’s own abilities paid off, and the trait got passed down. In particular, being overconfident was an advantage when there was uncertainty about an opponent’s strength, and when the reward for winning was high relative to the cost of competing. In other words, being overconfident helped competitors make the right—that is, the most profitable—decision [$].
• When the researchers tweaked the model to have three competitors instead of two, the same effect appeared: Overconfidence still led to success.

What’s the Context:

• A large body of research has shown that people are routinely overconfident, overestimating their financial acumen, leadership skills,driving abilities, and even attractiveness. If overconfidence sometimes confers an evolutionary benefit, as this study suggests, that could help explain why it’s so widespread.
• But, the researchers point out, these findings only apply to conflict and overconfidence on a small scale. Our tendency to have too much faith in our abilities may help explain current events caused in part by overconfidence—wars in which one side overestimated their power, the recent economic collapse—but it doesn’t have the same benefit in large, complex societies that it might in one-on-one competition. Overconfidence is like the body’s tendency to crave extra calories, the researchers say: an advantage at the time modern humans evolved, but sometimes a pitfall in today’s world.

References: 

• Dominic D. P. Johnson & James H. Fowler. “The evolution of overconfidence.” Nature, September 15, 2011. DOI: 10.1038/nature10384
• Matthijs van Veelen & Martin A. Nowak. “Evolution: Selection for Positive Illusions.” Nature, September 15, 2011. DOI: 10.1038/477282a