Is Left Brain vs. Right Brain a Myth? A Neurologist Explains

The idea that people are either "left-brained" or "right-brained" is a popular concept. It suggests that an individual’s personalities, talents, and ways of thinking are determined by which side of the brain is dominant.

Left-brained individuals are often described as logical, analytical, and skilled with numbers and language. In contrast, right-brained people are seen as creative, intuitive, and artistic. But how much truth is there to this popular theory?

Constance Katsafanas, D.O., a vascular neurologist at Marcus Neuroscience Institute at Boca Raton Regional Hospital, part of Baptist Health, often encounters this very question.

“One of the coolest questions that I get asked as a neurologist is: are we left brained or are we right brained, or both,” explains Dr. Katsafanas in a recent Baptist Health Instagram reel. The answer, backed by modern neuroscience, is more complex and interconnected than the simple left/right division suggests.

The Origins of the Left Brain/Right Brain Theory

The popular theory has roots in legitimate scientific discovery. In the 19th century, researchers found that patients with injuries to specific areas of the left side of the brain often had trouble with language. This led to the understanding that the brain has specialized regions for different tasks, a concept known as lateralization.

This idea gained more widespread attention through the work of Nobel Prize-winning neuropsychologist Roger W. Sperry in the 1960s. His research on "split-brain" patients, whose connections between the two brain hemispheres were severed to treat severe epilepsy, revealed that each side of the brain could function independently and appeared to have specialized abilities. This research was foundational but was later simplified by popular culture into the rigid personality labels widely recognized today.

Debunking the Myth: How the Brain Really Works

While it is true that certain functions are more dominant on one side of the brain, the idea that we are ruled by one hemisphere over the other is a myth. The two sides of your brain are in constant communication, working together to perform even the simplest of tasks. This communication happens through a thick bundle of nerve fibers called the corpus callosum.

Dr. Katsafanas explains the general distinctions that neurologists observe.

“Generally speaking, we think of functions like speech and language living on the left side, and things like thinking about where you are in space and paying attention to the other side of your body as sort of living on the right side,” explains Dr. Katsafanas.

This specialization, or lateralization, is real. However, she quickly adds a crucial point: “But that's not true for everybody.”

Modern brain imaging technology gives us a window into the brain's real-time activity, confirming that the two hemispheres are partners, not competitors. Dr. Katsafanas describes how neurologists see this partnership in action.

“We do a special test called a functional MRI (magnetic resonance imaging), and show people pictures or ask them to do math problems or reasoning puzzles. We see both sides of the brain light up … they talk to each other all the time,” said Dr. Katsafanas.

A functional MRI, or fMRI, is an imaging technique that measures brain activity by detecting changes in blood flow. When an area of the brain is in use, it requires more oxygen, and the fMRI can pinpoint this increased activity. These tests consistently show that complex activities, whether analytical or creative, require input from both hemispheres. Furthermore, the brain can be surprisingly flexible

As Dr. Katsafanas points out, “in some people, the language center lives on the right side.” This demonstrates that the brain’s organization is not universally identical.

The Brain as a Unified, Creative Network

So, if an individual is not strictly left-brained or right-brained, what does that mean for hir or her personality and abilities? It means a person’s brain is a far more powerful and integrated organ than the simplified myth allows.

The ability to solve a math problem might heavily involve logical centers in the left hemisphere, but it also requires creative problem-solving and spatial reasoning often associated with the right. Similarly, creating a piece of art involves not just the right hemisphere's creativity, but also the left hemisphere's role in planning and executing the fine motor skills required.

The concept of neuroplasticity—the brain’s ability to reorganize itself by forming new neural connections—further dismantles the rigid left/right brain idea. The brain can adapt and change throughout your life, creating new pathways and even reassigning tasks to different areas, especially in response to injury or learning.

Instead of limiting yourself to a label, it is more accurate and empowering to view your brain as a single, dynamic entity. Dr. Katsafanas offers this perspective. “So, instead of thinking of yourself as more right-brained or more left-brained, just think of your brain as a giant ball of creativity that makes you who you are.”