In the two-thousands, the magician-comedians Penn and Teller hosted a television series called Bullshit! In it, they took on a variety of cultural phenomena they regarded as worthy of the titular epithet, from ESP to Area 51, exorcism to creationism, feng shui to haute cuisine. Their sardonic arguments were enriched by clips of assorted interviewees —speaking in defense of the topic of the day. Penn once addressed the viewers, saying that we might wonder why anyone agrees to come on the show, given how they must know it will make them come off. But everyone, he explained, confidently believes that their own ideas are the correct ones.That episode came right to mind while watching the new Veritasium video above, which deals with the phenomenon of overconfidence. Like the oft-cited 93 percent of Americans who believe themselves better drivers than the median, we all fall victim to that affliction at one time or another, to one degree or another; the more interesting matter under investigation is why that should be so.One can always point to what T. S. Eliot called “the endless struggle to think well of themselves”: wanting to believe that we know it all, we take pains to present ourselves as if we do. But as explained by the professors interviewed here, Carnegie Mellon’s Baruch Fischhoff and Berkeley’s Don A. Moore (author of Perfectly Confident: How to Calibrate Your Decisions Wisely), the research has also revealed other potential factors in play.One important candidate is, as ever, stupidity. Much has been made of the Dunning-Kruger effect, previously featured here on Open Culture, which holds that the less competent people are at a task, the more confident they tend to be about their ability to perform it. That would seem to accord with much of our everyday experience, but we should also consider the role played by the basic cognitive limitations that apply to us all. Our brains can only process so much at once, and when they come up against capacity, they default to simplified, and often too-simplified, versions of the problem before them. It all becomes more difficult if we’re insulated from direct, objective feedback, a condition that often results from the kind of success and esteem that can be achieved by projecting — you guessed it — confidence.Related content:Why Incompetent People Think They’re Competent: The Dunning-Kruger Effect, ExplainedJohn Cleese on How “Stupid People Have No Idea How Stupid They Are” (Otherwise Known as the Dunning-Kruger Effect)24 Common Cognitive Biases: A Visual List of the Psychological Systems Errors That Keep Us From Thinking RationallyWhy Incompetent People Think They’re Amazing: An Animated Lesson from David Dunning (of the Famous “Dunning-Kruger Effect”)Penn Jillette Makes the Philosophical & Pragmatic Case for LibertarianismBased in Seoul, Colin Marshall writes and broadcasts on cities, language, and culture. His projects include the Substack newsletter Books on Cities and the book The Stateless City: a Walk through 21st-Century Los Angeles. Follow him on the social network formerly known as Twitter at @colinmarshall.