Are you a stable genius with a high IQ? Nobody knows more about the Dunning-Kruger effect than you!

Phil Whitby  

Have you ever bought a piece of furniture from IKEA (and subsequently valued it very highly) and decided you could build it without reading the instructions? How did that turn out?

If you answered in the affirmative you may be suffering from the Dunning-Kruger effect. Aside from everybody’s favourite president, sufferers demonstrate specific behaviours such as:

  • Overestimating their skill levels
  • Ignoring or failing to recognize skill in others around them
  • Ignoring or failing to recognize any mistakes they make
  • Bragging about their abilities and how quickly they achieve excellence

The most famous example Dunning and Kruger discovered was that of a bank robber who wore lemon juice on his (maskless) face during robberies. Since lemon juice was the main component of invisible ink, he surmised, it would have the effect of making his face invisible to the security cameras.

This example is especially gratifying as the perpetrator was applying a small amount of knowledge to a problem, and was willing to bet his future liberty on it. We are surrounded by people who learn a new fact and are keen to assume the mantle of expert and adjudicator of all regarding the subject.

To compound the obvious issues with Dunning-Kruger sufferers, those who do not suffer from it tend to underestimate their abilities relative to others. It may be that their self-assessment is reasonably accurate, but they tend to perceive others as being better-informed than they actually are.

The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt. - Bertrand Russell

I would argue that the primary value of interviewing a potential employee is that it allows you to weed out candidates that are prone to Dunning-Kruger tendencies. This is much more difficult to do on paper as it would be hard to distinguish a boastful from a genuinely accomplished individual. Even more significantly you may find a candidate who is downplaying their abilities in an area of competence. Dunning and Kruger demonstrated that women tended to underestimate their scientific reasoning ability even when the test results indicated no gender difference in performance.

These lessons can be applied to clients too: it may be more difficult and expensive to manage the expectations of a client with Dunning-Kruger than it is to keep their business, as the chances of conflict and/or unreasonable development demands increase in these cases.