Overconfidence leaks out through very specific language.
There is a special kind of silence that follows certain phrases, the kind where everyone in the room quietly realizes someone is not nearly as sharp as they believe. The mismatch between confidence and depth shows up in language long before it shows up in results. Psychologists who study reasoning, bias and intellectual humility keep circling back to the same idea. Truly smart people leave room for doubt. Those who only want to sound smart often give themselves away in seconds.