Trivially informative semantic context inflates people's confidence they can perform a highly complex skill.

Some research suggests people are overconfident because of personality characteristics, lack of insight, or because overconfidence is beneficial in its own right. But other research fits with the possibility that fluent experience in the moment can rapidly drive overconfidence. For example, fluency can push people to become overconfident in their ability to throw a dart, know how rainbows form or predict the future value of a commodity. But surely there are limits to overconfidence. That is, even in the face of fluency manipulations known to increase feelings of confidence, reasonable people would reject the thought that they, for example, might be able to land a plane in an emergency. To address this question, we conducted two experiments comprising a total of 780 people. We asked some people (but not others) to watch a trivially informative video of a pilot landing a plane before they rated their confidence in their own ability to land a plane. We found watching the video inflated people's confidence that they could land a plane. Our findings extend prior work by suggesting that increased semantic context creates illusions not just of prior experience or understanding-but also of the ability to actually do something implausible.