According to University of Utah psychologists David Strayer and David Sanbonmatsu, people who identify as strong multitaskers tend to be impulsive, sensation-seeking and overconfident in their ability to juggle multiple tasks simultaneously. In fact, note the researchers in the latest issue of PLOS, the people who multitask the most are often the least capable of doing so effectively.

A full seventy percent of participants rated themselves as above-average at multitasking. It’s a result fans of Garrison Keillor will be quick to find the humor in. “[These people] all think they live in Lake Wobegon, where everybody is above average,” said Strayer in a statement. “But it’s a statistical impossibility.”

What’s more, “the people who are most likely to multitask harbor the illusion they are better than average at it,” says Strayer, “when in fact they are no better than average and often worse.”*

In short: just because you multitask a lot doesn’t mean you’re good at it. In fact, say the researchers, what you interpret as “multitasking” may actually be a symptom of an inability to focus on one task at a time, causing you to become distracted, or seek stimulation in some other activity. The study’s findings corroborate this, revealing that the more time someone spends on their phone while driving, or using multiple forms of media simultaneously, the more likely they are to perform poorly on a standardized test of multitasking abilities.

But here’s what’s really ironic: the test subjects who performed best on the OSPAN multitasking test — we’re talking the top 25% here — were found to be the ones least likely to multitask, and most likely to just do one thing at a time. Many of the world’s best multitaskers are squandering their gift, and they probably don’t even know it.