The Dunning Kruger Effect

Sign Up For Weekly Tips! Get Trevor’s Weekly Tips Straight To Your Inbox!

The Dunning Kruger effect is attributed to two psychologists from Cornell who did some research that uncovered results that are both humorous and unsurprising (to me): many people think they are great even though their work results are terrible.

How the Dunning Kruger effect was discovered

In 1996, Macarthur Wheeler walked into a Pittsburgh bank and demanded money.  His face was wet and he looked full into the security camera blinking his eyes heavily.  He walked down the street and robbed another bank, and then went home for dinner.

Police reviewed the security tapes, and shortly after dinner were at Wheeler’s home to arrest him.  He was shocked.  “But I was wearing the juice!” he stammered.

The story came out that somewhere Wheeler had read that lemon juice causes invisibility.  So he sprayed lemon juice on his face, and determined not to get near a heat source (which would render his superpower useless).

Psychologist David Dunning watched the news report and wondered if this had wider application.  Could it be that we’re not very good at recognizing our own competence and lack of it?

Turns out this is exactly the case.  This is called the Dunning-Kruger effect.

Your worst think they are your best

Not only are the incompetent unaware of their incompetence; they also often feel confident that they are very competent indeed.

The study involved administering tests to groups of people, scoring their performance, and then asking participants to rate their level of competence compared to other participants.  Frequently, those who scored in the bottom 10% of participants judged their performance to be in the top third of the group.

This happens in every industry.  Check out these stats from various studies:

  • 42% of software engineers rate their skills as being in the top 5% of the company
  • In a study of faculty members at the University of Nebraska, 68% rated themselves in the top 25% for teaching ability, and more than 90% rated themselves ‘above average.’ (This is of course mathematically impossible)
  • 21% of Americans believe that it’s ‘very or fairly likely’ that they’ll become millionaires within the next 10 years

This is the Dunning Kruger effect.  Your worst performers think they’re a lot better than they are!

Your best think they aren’t that great

Meanwhile, the best performers on your team think they have a long way to go.  They question their competence, and assume that they don’t make the mark like they should.

In another study of 30,000 employees, only 29% said they ‘always know where their performance should be.’  36% responded that they ‘never or rarely know.’

And you don’t want to use my coach and connect form.

This  is why I wrote “The Power of People Skills.”  Employees are willing to improve and work to get better, but they need input and coaching.  Our job isn’t complicated:

  1.  Hire the best people possible
  2. Tell them clearly what you want them to do
  3. Give them regular feedback and coaching to help them be their best

And this week, ask yourself this tough question:  “Are my underperformers aware that I think they are under performing?”

Maybe it isn’t their fault.

Trevor Throness head shot 2019

Trevor Throness is a speaker, consultant, and author of “The Power of People Skills.”  He is also co-founder and senior instructor at

Find more about “The Power of People Skills” here:

Recommended Resources:

Uncover your strengths and weaknesses with our complimentary assessment. Boost your effectiveness at work and with your team.

Free Resource Library: Access our extensive collection of valuable resources for instant support in your personal and professional growth.

Explore Our Course Library:

Enhance your leadership skills with our diverse selection of courses. Take your abilities to the next level and become a more effective leader and team player.
Written by Trevor Throness
Trevor is a veteran coach, keynote speaker, and the author of the book “The Power of People Skills” released by Career Press NY in 2017. He’s also written for or been featured in places like Forbes, Inc, The NY Post, The Globe and Mail, Entrepreneur, CEO Magazine, and numerous podcasts and interviews.


Our Clients Love the Professional Leadership Institute

Your team will, too! Check out some reviews from our students.
The PLI program was invaluable to our network.
The range of topics delivered, the open dialogue, experience, and examples that PLI brought to each session were outstanding and provided a path for our Franchisees and Managers to look at leadership, coaching, and connecting with their teams in a new light. Many have implemented these strategies in their bakeries and have seen immediate results.
Michelle C.
COBS Bread
Highly recommend to help your team move forward
We have locations around BC and Alberta, so getting people on the same page can be very difficult... Until now. Our entire management team and location managers take the same great courses and then meet monthly online with our coach to apply it to our situation. People are engaged, the courses are excellent, we love our coach, and we are all learning together!
Jason Fawcett
President, Kelson Group
The result has been a transformation of our culture. 
We decided to implement PLI's strategies across the country in over 150 locations and over 3500 employees.  The result has been a transformation of our culture.  People's lives have been positively impacted - professionally and personally.  Morale is high and sales and profits are up as a result.
Daryl Verbeek
Daryl Verbeek
We’ve learned how to fix ongoing personnel issues once and for all
The roadmap laid out set our business up to quintuple in sales.  We've learned how to fix ongoing personnel issues once and for all, attract top talent, and spend our time focused on results, not internal staffing problems.  I highly recommend PLI to you - it's worked for us!
John DeJong
Satisfied Client
I had no idea that running a business could be this fun!
In less than 18 months of working with Trevor, he has transformed my business from being average to exceptional, where mediocrity is not acceptable, where being great is standard.  Working with PLI has allowed me to realize my dream of not simply owning a job, but owning a business.
Justin Bontkes
Principal, Caliber Projects
Our culture has taken major steps forward this year
Our culture has taken major steps forward this year with Trevor’s help.  He is funny, relatable, and his tools are very very practical and have helped us focus and upgrade our teams throughout our retail network. Trevor recently spoke to an employee group, and one person remarked, “I could listen to Trevor all day.”   We would highly recommend Trevor.
Stan Pridham
Founder, KMS Tools
The results have been remarkable
At first, we resisted, “This just won’t work with a law firm.” But we persisted and the results have been remarkable: our client base and profits have steadily improved, and staff engagement and morale is the healthiest its ever been.
Doug Lester
Partner, RDM Lawyers
Helped our fast-growing business become what it is today
I've experienced PLI's approach first hand and it's been crucial to sustaining our growth.  I can't imagine a business that wouldn't benefit greatly from his help.
Brian Antenbring
Founder, TEEMA
Provided practical ways to make positive changes
Trevor was incredibly well-received by the entire organization. He was able to articulate people issues that many of our franchisees were experiencing and provided them with practical ways to make positive changes. We have implemented the Star Chart tool across the organization and see it as vital to building happy, effective teams.
Aaron Gillespie
President, COBS Bread
Scroll to Top

Start Learning Today

For Individuals

Unlock your potential and accelerate your career with sought-after management and leadership skills.


Transform Your Organization

For Teams

Book a consultation to discuss your challenges and discover how we can help you build a winning team.


Sign Up For Weekly Tips!

Get Weekly Coaching Tips Straight To Your Inbox Every Monday.