Today I feel scientifically vindicated.  I have often said that bad candidates over-rate their abilities, while good ones under-rate their abilities.  If you ask two job applicants “On a scale from 1 to 10, how proficient are you with Excel?” the more skilled person will often rate themselves lower than the less skilled person.   I know this because I used to work in a place that  tested people’s computer skills after they rated themselves.

There are several explanations for this behavior.  One explanation is that top performers set higher standards for their own performance.   Another explanation is that the more a person knows about Excel, the more they realize just how much they still do NOT know about Excel.

But today, Jason Seiden wrote a post about the Dunning-Kruger effect – where Cornell scientists showed that Darwin was right when he said, “ignorance more frequently begets confidence than does knowledge.” They went on to note that and “people with true knowledge tend to underestimate their competence.”  Sweet, sweet scientific vindication for one of my long-held opinions.

[Update July 2020] Studies also show that women don’t self promote as much as men. The researchers noted that, “In every setting we explored, we observed a substantial gender gap in self-promotion: Women systematically provided less favorable assessments of their own past performance and potential future ability than equally performing men.”

Have you ever hired someone incompetent?  Think back to the interview.  Odds are you asked them to assess their own ability to do the job.  They exuded confidence and most humans prefer to listen to and believe someone confident.

But if less competent people are often more confident, and are more likely to over-rate their abilities – then asking people to rate themselves is a virtually foolproof way to hire the wrong person.  Frankly, if you ask people to rate themselves on their abilities, it would surprise me if you ever hire anyone competent to do the job.

So when you are interviewing,  instead of asking people to rate their abilities, ask them specific questions about what they have done, and then apply your own rating scale.  Their opinion of their own abilities is virtually irrelevant.

If you’d like to stop wasting your time on the irrelevant, superficial aspects of interviewing, and start understanding the deeper elements of what really predicts success a new hire, read our post on How to Conduct a Job Interview so Top Performers Actually Want to Take Your Job.

And, if you prefer all that research and information pulled together into one attractive document you can easily share with others, download our Employer Guide to Interviewing.