Have you ever been told you're "left-brained" because you're analytical, logical, and good at math? Or perhaps you've been described as "right-brained" because you're creative, artistic, or intuitive. It's one of the most popular ideas in pseudoscience, and one of the most misunderstood. The truth is that there is no scientific evidence that people are either "left-brained" or "right-brained." While the two hemispheres of the brain do perform some specialized functions, modern neuroscience has shown that nearly all of our daily thinking relies on both sides working together.

​

One of the strongest pieces of evidence comes from a study by Jared A. Nielsen, Brandon A. Zielinski, Michael A. Ferguson, Janet E. Lainhart, and Jeffrey S. Anderson, published in PLOS ONE in 2013. Their research directly tested the popular left-brain/right-brain hypothesis using brain imaging—and found no evidence that people are globally dominated by one hemisphere.

 

Where Did the Myth Come From?

​

The myth has its roots in real neuroscience. Beginning in the 19th century, scientists discovered that some brain functions are lateralized, meaning they are more strongly associated with one hemisphere than the other. For example:

​

• In most people, language production is primarily located in the left hemisphere.

• Some aspects of spatial attention are more strongly associated with the right hemisphere.

 

These findings are well established. Unfortunately, over time these genuine discoveries were exaggerated into the idea that entire personalities could be explained by one hemisphere "dominating" the other. That's where the science ends, and the myth begins.

 

Putting the Myth to the Test

​

Rather than relying on personality questionnaires, the researchers examined the brains of more than 1,000 healthy individuals using resting-state functional magnetic resonance imaging (fMRI). Resting-state fMRI measures communication between different brain regions while a person is not performing a specific task. It allows researchers to see which areas naturally work together as functional networks. If the popular belief were true, some individuals should consistently show stronger connectivity throughout the left hemisphere, while others should show stronger connectivity throughout the right hemisphere. That's exactly what the researchers looked for.

 

What They Found

​

The brain certainly contains regions that are more active on one side than the other.

However, the researchers found no evidence that people have an overall "left-brained" or "right-brained" brain organization. Instead:

​

• Some individual brain networks showed stronger left-sided organization.

• Other networks showed stronger right-sided organization.

• These differences occurred locally, not across the entire brain.

 

In other words, a person might have stronger left-sided activity for one function and stronger right-sided activity for another. There was no consistent pattern that divided people into "logical left-brained" and "creative right-brained" groups.

 

Does the Brain Have Specialized Hemispheres?

 

Absolutely. The study does not claim that the two hemispheres are identical.

In fact, brain lateralization is one of the defining features of human neuroscience. Examples include:

​

• Language is usually concentrated in the left hemisphere.

• Facial recognition often relies more heavily on the right hemisphere.

• Motor control is largely crossed, meaning the left hemisphere controls the right side of the body and vice versa.

 

These are real and well-established findings. What the study challenges is the idea that an entire person's thinking style can be explained by one hemisphere dominating the other.

 

Why the Myth Persists

​

The left-brain/right-brain theory survives because it's simple. People enjoy personality categories. They make complicated human behavior feel easy to understand. Unfortunately, the brain isn't nearly that simple. Creativity, for example, involves memory, attention, planning, emotion, language, and visual processing. These functions recruit networks spread throughout both hemispheres.

Likewise, solving a mathematical problem doesn't rely exclusively on the left hemisphere. It requires visual processing, working memory, attention, reasoning, and executive control distributed across many interconnected regions. The brain works less like two competing teams and more like a highly coordinated orchestra.

 

What Neuroscience Says Today

​

Modern neuroscience views the brain as a collection of interconnected networks rather than isolated centers.

Although certain functions show lateralization, nearly every complex behavior—from reading a novel to painting a picture—depends on communication between both hemispheres through a thick bundle of nerve fibers called the corpus callosum. Rather than asking whether someone is "left-brained" or "right-brained," neuroscientists are much more interested in how different brain networks work together.

 

The Bottom Line

​

The idea that people are either left-brained or right-brained makes for catchy social media posts and entertaining personality quizzes, but it isn't supported by modern brain imaging research. Yes, the two hemispheres have specialized functions. No, people are not globally dominated by one side of their brain. Whether you're solving an algebra problem, composing music, writing a novel, or designing a building, your brain is relying on billions of neurons communicating across both hemispheres. In other words, you're not left-brained or right-brained. You're whole-brained.

 

Original Study

​

Nielsen, J. A., Zielinski, B. A., Ferguson, M. A., Lainhart, J. E., & Anderson, J. S. (2013). An Evaluation of the Left-Brain vs. Right-Brain Hypothesis with Resting State Functional Connectivity Magnetic Resonance Imaging. PLOS ONE, 8(8), e71275.

Read the original article:

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0071275