Skip to main content

Verified by Psychology Today


Brain Blindness

Part 1: How cognitive biases blind your brain.

Source: Kjell Kuehn/Pexels
Learn how to overcome brain blindness.
Source: Kjell Kuehn/Pexels

It may seem like a small matter, but the ability to identify color and the differences between colors dramatically impacts a person’s life. For example, imagine not being able to identify the color green. How are you to navigate stop lights? You’ll be going when others are stopping; stopping when others are going; or, proceeding into traffic and possibly get hit. Yikes! Or, let’s say, on the lower rung of life-threatening situations, you have a major craving for green peppers and you wind up making a meal with all red peppers. Yuck! Needless to say, life gets a lot harder when you can’t see and distinguish between colors. Now imagine if your brain was blind, insofar that your brain is blind to the judgments and lines of reasoning that make logical and factual sense, and the thoughts that don’t. Scary, right? What’s more important than being able to accurately discern what is fact from fiction, what is biased from unbiased. Well, in case you didn’t know, there is a name for this, the Dunning-Kruger effect.

The Dunning-Kruger effect is a cognitive bias identified by social psychologists David Dunning and Justin Kruger in their 1999 study “Unskilled and Unaware of it.”[1] The Dunning-Kruger effect states that people with little knowledge and low social ability lack an objective self-assessment and tend to overestimate their skill/ability.

To imagine how this works visually, think of an inverse bell curve. On the left side where the tail is high, you find the group of people who have low knowledge and low experience, but high confidence and positive self-ratings (high confidence and low competence). This group tends to overestimate their performance when it is in fact poor, and they struggle to make accurate self-assessments. Socrates famously said, "The more I know, the more I realized I know nothing." This group's motto could easily be the reverse, "The less I know, the more I realized I know everything." They simply don't know enough to know how little, in fact, they really know.

Then the curve drops dramatically in the middle. This middle is occupied by a group of people who know enough to realize they aren't experts and thusly, have low confidence in their knowledge and skills (low confidence and low competence). On the right-hand side, the curve rises—this group of people is made up of true experts who deservedly should be confident (high competence + moderate confidence). Oddly enough, experts are not nearly as confident as the low knowledge group on the left-hand side. Why? Experts compare themselves relative to others they believe to be more knowledgeable and competent. This has also been colloquially termed the “imposter syndrome.” To learn more about the Dunning-Kruger effect, read this article.

Between the three groups, we should be most worried about the ones who are ignorant, but over-confident. More specifically, the primary concern should be that we, ourselves, are in this group. I don’t fear a cautious, self-critical, intelligent person. I do fear an ignorant, un-self-aware, incompetent person. This is the kind of person who, at worst, makes mistakes without knowing it, or, at best, may possess a modicum of knowledge, but can’t admit when a mistake has been made. Both scenarios are troublesome. Both scenarios can carry grave consequences.

But let’s step away from the worst scenario and imagine one a little more down to earth, one that’s more anchored in person-to-person, day-to-day experience. What if someone you know and love is simultaneously over-confident and under-informed; poorly performing and oblivious to their own mistakes? Your best efforts to have meaningful discourse with that person will be futile. They won’t have the presence of mind to consider the weaknesses in their own view and performance, or the merits of yours. They are essentially self-inoculated to reason; they are anesthetized to truth. This is not only bad from an intellectual perspective, but it’s also bad from a mental health and relational perspective.

A person experiences growth when their perspective is expanded. When they are open to new ideas and perspectives, even ones that challenge their own. We are better for hearing the voices of others. It expands our empathy; it hastens us to listen before speaking. We are never harmed, objectively, by more information. The only casualty of additional information is ignorance. But when our minds are closed and blind, there is what economists call an opportunity cost. The time we spend resisting and fighting new information and perspectives is time we could have been learning and growing that we can’t recover once lost.

Furthermore, a person is a better spouse, parent, family member, friend, co-worker, and community member when they are open rather than closed to new ideas and perspectives. To steal a concept from the couples counseling field, psychologist and researcher John Gottman has found that intimate partners report higher levels of relational satisfaction when each partner is open to influence.[2] That means relationships thrive when people don’t immediately shoot down ideas, and the people offering them. We are made better for listening and receiving feedback. We are made better for asking questions and entertaining viewpoints that are not our own.

Gottman’s research isn’t just true for intimate relationships, but for any kind of important relationship that makes up a person’s social support network. Preserving and expanding your social support network is kind of a big deal. A healthy social support network has been linked with a number of positive mental health outcomes[3] and, most notably, with longevity.[4] But how can you enjoy rich, long-lasting relationships if you believe there is nothing for you to learn from others and you have all the answers? A person who believes as such is rather unattractive as a friend, spouse, family member, or co-worker.

Let’s suppose someone develops a severe case of major depressive disorder while simultaneously suffering from the Dunning-Kruger cognitive bias. The most effective psychotherapeutic treatment for depression is cognitive-behavioral therapy, which, at its core, assists clients with examining and changing their thinking. As famed psychiatrist David Burns says “You feel the way you think.” How are they going to receive effective treatment if you, in principle, are resistant to reconsidering the way you think and believe? What I’m talking about isn’t purely theoretical. I’ve worked, or attempted to work with, many people who think there is nothing wrong with them, yet nothing in their life is working out. Rather than examining themselves and their thinking, they think everyone else is the problem.

To understand how to overcome brain blindness and regain cognitive clarity, read the second part of this two-part post, Overcoming Brain Blindness.


[1] Kruger, J., & Dunning, D. (1999). Unskilled and unaware of it: How difficulties in recognizing one's own incompetence lead to inflated self-assessments. Journal of Personality and Social Psychology, 77(6): 1121–1134.

[2] Retrieval date: March 11th, 2020.

[3] Chu, P. S., Saucier, D. A., & Hafner, E. (2010). Meta-Analysis of the Relationships Between Social Support and Well-Being in Children and Adolescents. Journal of Social and Clinical Psychology, 29 (6): 624-645.

[4] Olsen, R. B., Olsen, J., Gunner-Svensson, F., & Waldstrøm, B. (1991). Social networks and longevity. A 14 year follow-up study among elderly in Denmark. Social Science & Medicine, 33 (10): 1189-1195.

More from Dan Bates, LMHC, LPCC, NCC
More from Psychology Today