Neuroscience research shows that the left-brain, right-brain dominance theory is a myth. Learn about the implications of this new knowledge of the brain.
The left-brain, right-brain dominance theory of personality is one of the more persistent myths about the brain.
This theory claims that people can be divided into two distinct groups — left-brained people who are analytical and right-brained people who are creative.
This belief was born after certain discoveries about the workings of the brain were made over 100 years ago.
But with recent advances in neuroscience, the concept of left-brain versus right-brain dominance is now obsolete.
How the Left-Brain, Right-Brain Myth Began
The brain is comprised of two distinct halves known as cerebral hemispheres.
However, these hemispheres are not mirror images of each other — the brain is asymmetrical in both form and function.
The two sides of the brain communicate with each other via a band of nerve fibers called the corpus callosum.
In the 1880s, it was noted that damage to half of the brain resulted in predictable changes in behavior and brain function.
It was observed that language abilities resided in structures in the left side of the brain, while areas that governed spatial abilities were found in the right side.
Fast-forward to the 1960s when neurosurgeons performed split-brain surgery on patients with severe epilepsy.
Split-brain surgery involves severing the connection between the two hemispheres.
This drastic procedure worked to stop seizures, but the cost was often loss of specific brain functions.
By carrying out experiments on these split-brained patients, neuropsychologists were able to correlate areas of the brain with their functions.
They discovered that each brain hemisphere was dominant for different kinds of behaviors.
The right side of the brain was thought to be mainly responsible for spatial abilities, facial recognition, visual imagery, and music, while the left side governed calculations, math, and logical abilities.
The head of this research, Roger Sperry, received a Nobel Prize for this work, bringing the left-brain, right-brain concept to the attention of the public.
According to the left-brain, right-brain dominance theory, everyone has a dominant brain hemisphere and this is a major determinant of basic personality type.
“ Some of the greatest minds of all time were both analytical and creative. Leonardo da Vinci was a scientist, mathematician, engineer, and inventor who painted the “Mona Lisa,” one of the most famous paintings in the world.
Typical right-brain characteristics include creativity, expressiveness, intuitiveness, and emotional and artistic tendencies.
Representative left-brain attributes include being logical, analytical, and good at language, math, and science.
The illustration below sums up the theoretical concept of these two personality types nicely.
Why the Theory of Left vs Right-Brain Dominance Is Obsolete
The concept of left-brain, right-brain dominance never did have a strong foundation in science, and now this theory has been totally debunked.
Brain scan technology reveals that the two brain hemispheres communicate through the corpus callosum and work together to perform a wide variety of tasks.
For example, language processing, previously thought to be a left-brain activity, does not take place in any one side or region of the brain.
It’s thought that the left side of the brain processes grammar and pronunciation, while the right side processes speech patterns and intonation.
Of course, some people are better at languages than others, but this is not because they are left brain-dominant.
Language involves the whole brain.
In a groundbreaking study, neuroscientists scanned over 7,000 brain regions in more than 1,000 people to analyze brain activity patterns.
So now, the prevailing theory is that we use both sides of our brain as needed, depending on the task at hand.
For most tasks, the brain recruits information from various brain regions via networks of interconnected neurons that act as information highways in the brain.
Why the Left-Brain, Right-Brain Myth Persists
The scientific case against the left-brain, right-brain dominance theory is strong.
It was always considered pop psychology by most in the scientific community and was never widely accepted.
While different personality types exist, it’s quite clear that they have nothing to do with whether one brain hemisphere is more active, stronger, or more connected than the other.
And yet this myth persists anyway.
Here are four possible explanations for why the world-at-large won’t let this brain myth die:
1. It takes time for a new idea to go mainstream, so it could be just a matter of time.
It takes an average of 17 years for a new medical discovery to be adopted by mainstream medicine and even longer to trickle down to the general public.
2. Generalizing and categorizing helps us make sense of our world.
Our understanding of the brain and human personality is really still in its infancy.
Dividing humanity into two main personality types has an appealing simplicity to it.
3. People yearn to understand themselves — why they are the way they are, and how they fit into the world.
They feel that the left-brain, right-brain concept helps them do that.
For similar reasons, personality quizzes and daily horoscopes are always popular.
4. An abundance of left-brain, right-brain tests, books, and apps found online lends credibility to the myth.
When you see something repeated often enough, you are more likely to believe that it’s true.
This is due to a cognitive bias known as the illusory truth effect.
The Social Downside of the Left-Brain, Right-Brain Myth
Believing in the left-brain, right-brain myth may seem harmless, but it’s not.
It hinders both personal and social progress.
Believing that you can be proficient at only certain skills or that your personality type is pre-determined can become a self-fulfilling prophecy.
It also means that we evaluate others from a left-brain vs right-brain perspective.
Stereotypical Thinking and Prejudice
This encourages stereotypical thinking and prejudice — “all artists are bad at math” and “engineers can’t be creative.”
Obviously, this is untrue.
Some of the greatest minds of all time were both analytical and creative.
Leonardo da Vinci was a scientist, mathematician, engineer, and inventor who painted the “Mona Lisa,” one of the most famous paintings in the world.
Nobel Prize-winning theoretical physicist Albert Einstein was an accomplished violinist with a lifelong passion for music.
He believed that the theory of relativity occurred to him by intuition, and that music was the driving force.
Effect on Education
Unfortunately, the left-brain, right-brain myth has infiltrated our education system.
Some teachers use it to label students as dominant in just one potential skill area, and have attempted to teach those students accordingly.
By depriving science-minded students of music lessons, we might be depriving the world of the next Einstein!
Watch the Video
World-renowned astrophysicist Neil DeGrasse Tyson is one of the most outspoken champions of science.
Why You Should Avoid Online Left-Brain, Right-Brain Tests
The prevalence of bogus brain dominance tests online is a way that marketers keep the public believing in the left-brain, right-brain myth.
You might be tempted to take one of these tests in the hope of learning more about yourself.
But, as you now know, they are based on a faulty premise and do you a disservice by strengthening self-limiting beliefs.
But what you may not know is that they can be used against you in unscrupulous ways.
Free Online Tests Exist to Profit From You
When websites offer free services like online psychology, mental health, or personality tests or quizzes, we’d like to think that they are genuinely helpful.
While some online tests are created by reputable organizations or educational institutions, that will not be the case with left-brain, right-brain tests since there is no scientific merit to the underlying theory.
So these quizzes are designed for one purpose — to make money off you.
Profiting From Your Personal Information
While some sites lure you with a test to sell their products or services, the “product” may likely be your personal information.
The most innocuous test can gather more data about you than you might suspect, even if you reveal no personal details.
Organizations that mine data can easily tell what type of computer you use, your IP address, your location, and the sites you visited before and after you arrived at their site.
From there, it’s not hard to find your name, address, and a lot more about you.
Taking online tests, in general, puts you at risk for identify theft.
Evaluate Test Websites
So, before you take a brain dominance test (or any online test, quiz, or survey), browse around the site.
Is there a reputable organization behind it?
Someone spent time and money creating this test.
What do you think their motivation is?
Beware of sites that do not have an “about us” page, contact information, disclaimers, or privacy notices.
Sites that do not include this information should be regarded with suspicion.
Left-brain, right-brain tests may ask questions like whether you are orderly, a risk taker, impulsive, punctual, good in math, or have good communication skills.
Can you see why this information might be interesting to others — like a potential employer or insurance company?
Pay attention to the questions and listen to your feelings.
If a test and website do not project trustworthiness, don’t take their test.
Recommended: Upgrading brain health is key to making your brain work better.
Brain supplement can help you:
- Improve your mental clarity and focus.
- Boost your memory and your ability to learn.
- Increase your capacity to think critically, solve problems, and make decisions.
P.S. Like what you’ve read on this page? Get more like this — Sign up for our emails.