The Dunning-Kruger Effect: Why the Least Competent Are Often the Most Confident

The person in the room speaking with the most confidence isn't reliably the most competent person on the topic. In this episode, Andrew and Hannah dig into David Dunning and Justin Kruger's 1999 research and the mechanism behind it: the same skill needed to perform well at something is often the same skill needed to judge that performance accurately, which means low competence creates a double burden — not knowing what you don't know.

We cover the mirror-image pattern at the high-competence end, where skilled people, because a task is easy for them, often assume it's similarly easy for everyone else. We explore the direct application to leadership: newly promoted managers are disproportionately likely to be in a low-competence, high-confidence zone, since management is a genuinely different skill than whatever earned them the promotion — and how this connects to the Peter Principle as a psychological explanation for why someone doesn't notice their own mismatch.

We also dig into a more hopeful finding: confidence often dips before it rises as real competence develops, meaning a leader's confidence dropping a few months into a new role can actually be a sign of growth. We close on the uncomfortable implication that a genuine expert's calibrated uncertainty can look less trustworthy than a novice's unwarranted certainty.

Speak Leadership explores the many forms and dialects of leadership.

Topics covered: Dunning-Kruger effect, confidence, competence, self-assessment, new managers, leadership development, the Peter Principle.