You would think, wouldn’t you, that having a lot of self-confidence would help your chances of success in online dating. And you’d be right! Mostly. But there happens to be one very specific group that has no business being overly self-confident in online dating, as it appears to harm them rather than help: college-age guys. The more confident these young men are, the less success they see on the online dating site OKCupid, according to research led by Carnegie Mellon University’s Emily Yeh, who presented her findings recently at the Society for Personality and Social Psychology’s annual meeting in San Diego.

To be fair to these guys, overconfidence is not strictly a young-male thing. The scientific literature on overconfidence is filled with all of the varied and often hilarious ways people believe themselves to be better than average, a phenomenon known as illusory superiority. (It’s also sometimes called the Lake Wobegon effect, after the fictional town in A Prairie Home Companion.) Research has shown, for example, that people tend to believe their IQ is higher than average, or that they’re a better driver than average. And OKCupid’s data bears this out, too. The site asks its users to rate themselves on a variety of things, including intelligence, height, and morality. Just like in the psychology studies on illusory superiority, OKCupid users tend to rate themselves as being smarter and more moral than the average user of the site. Also, according to Yeh’s analysis of the data, it is highly likely that people lie about how tall they are. “They tend to say they are two inches taller than they probably are in real life,” something that became clear when Yeh compared the site’s data to national surveys.