By Jennider Santisi

An overconfident person is more likely to enter a contest even when the odds are stacked against them, or start a business even if it’s likely to fail. So why is overconfidence prevalent when there’s such a risk associated with having that personality trait?

Research shows the extensive reach of overconfidence as it spreads across networks and how it influences decisions, achievements, and relationships. The topic was explored during the symposium “Overconfidence: New Insights for its Roots and Consequences” at SPSP’s 16th Annual Convention in Long Beach, California.

Joey Cheng of the University of California at Irvine illustrated that overconfidence behaves almost like a virus—if you’re around an overconfident person, you might catch it. Cheng and her colleagues found that individuals surrounded by overconfident others are more likely to become overconfident as well.

Their study involved three generations of participants, and their results illustrate that not only is overconfidence socially contagious, but it can also “skip” a generation. First generation participants were observed to have a direct impact on the third generation, despite that these two generations were only indirectly connected via others in the second generation, making overconfidence contagious at two degrees of separation.

The saying usually goes that “two heads are better than one,” but research shows that might not be true. Julia Minson of Harvard University explains that, “using collaboration to make qualitative estimates is usually a good idea…it’s known as the wisdom of crowd effect. But the issue lies in the fact that people don’t want to do what others say is good for them…People adjust only about one-third of the way when they’re faced with the judgment of another individual.”

This one-third phenomenon means people aren’t really averaging their ideas with another individual’s. Instead, they actually think their ideas are slightly better than another’s, which leads to a cost in the accuracy of their judgment. The very process of working with someone versus alone may have a negative effect on collaboration.

Minson and her colleague Jennifer Mueller designed two studies to illustrate the effect of collaboration on accuracy and confidence. Participants went through three steps: generating an initial estimate, receiving advice from another individual or two individuals, and a final opportunity to revise the estimate based on the advice.

Two participants that initially worked together (dyads) reported three times as much confidence in their estimates. With this increased confidence, dyads adjusted their estimates significantly less when faced with advice, and their estimates were less accurate in the end. Participants who worked on their own reported less confidence in their responses, and adjusted their estimates to a greater extent than the dyads. In the end, the individual participants had greater accuracy in their estimates.

“We have two people who received input from two people, and they are not more accurate than one person who received input from one person. We’ve essentially just wasted the time of two brains,” Minson says. “The take away here is; dyads under-weigh peer input more than individuals… and the driver seems to be the greater confidence in the quality of the estimates. We often put together teams and groups hoping the collaboration will justify the result, but due to this phenomena, two people are doing the work that one could’ve done just as well.”

Why do we convince ourselves that we’re greater than we really are if there are such large costs? William von Hippel of the University of Queensland explains that one reason we use self-deception is to impress others, and the benefits of doing so outweigh the risks.

“Self-enhancement is a strategy you’re going to engage in when the difference between success and failure is large,” explains von Hippel. According to von Hippel, overconfidence plays a significant role in mate attraction and competition.

Von Hippel’s research indicates that overconfident people are perceived as more confident, leading to increased romantic desirability. But overconfident individuals are also perceived as more arrogant, which decreases romantic desirability. The cost of arrogance in diminished desirability was offset by the fact that participants were also less likely to compete for romantic partners with arrogant individuals.

Overconfidence appears to facilitate romantic success by attracting mates and repelling competitors. In the real world, these benefits of overconfidence often outweigh the costs, which may explain why it’s such a pervasive trait across cultures.