The myth of left brain vs right brain.

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Left vs Right

The left brain.

Logical. Analytical. Mathematical. Organized. Systematic.

The right brain.

Creative. Artistic. Intuitive. Spontaneous. Emotional.

We’ve used these two descriptions to facilitate job selections, team selections, team building activities, personality profiles and testing, parenting, teaching and a host of other things.

The appeal of the left-brain/right-brain split lies in how simple it is.

Some examples

Want to be more creative? Then what you can do is present information to the left visual field which for both eyes crosses over into the right hemisphere. This will activate your creative right hemisphere and give you awesome ideas.

Side note: It’s a common misconception that information from the left eye goes to the right hemisphere, and information from the right eye goes to the left. This is true of the body’s movement, but not the eyes. The left visual field of both eyes cross to the right hemisphere. The right visual field of both eyes crosses to the left. The crossover happens at the optic chiasm, located underneath the brain where the optic nerves cross each other. 

Feeling stuck with a problem at work? Get a team of right-brainers to dream up a creative solution for you. You can select the team using an online left/right brain inventory.

Stuck face to face in an interrogation with a suspect? Ask her a hard question. If she looks to the right, she’s accessing her logical left hemisphere and, therefore, telling the truth. If she looks to the left she’s accessing her creative right hemisphere and, therefore, lying.

The only problem with this classification, apart from making us lazy, is that it’s wrong.

The left-brain/right-brain idea is a myth.

The two brains

We clearly have two, distinct halves to our brains: the left and right hemispheres. They’re separated by the longitudinal fissure, which is the groove running from front to back, right in the middle of your brain.

Longitudinal fissure

Longitudinal fissure

Because some brain functions are located largely in one hemisphere or the other, we generalized to say the left side of our brain does one thing, and the right another.

We then generalized further to say people thought in that way or the other, so we were left-brained or right-brained. Having only two ways to categorize people is great, because we then don’t have to try very hard. You’re either one or the other.

Life gets way harder when we have a number of ways of classifying things, so two is simple.


Brodmann’s areas are the most enduring categorization system for the brain, developed by Korbinian Brodmann and based on how cells were structured and organized. We still use them. But Brodmann’s areas don’t suggest personality from location like the left-brain/right-brain split.

Maybe you remember phrenology, which inferred ability, personality and character from the shape of your skull.

The idea was that located in the brain were a range of distinct faculties, each with its own location. The size of the particular location was evidence of the power of that faculty. As the shape of the brain was believed to be accurately reflected on the skull, we could determine your mental and moral characteristics by examining your skull.

Neuroimaging studies tell us a different story, thanks to work carried out by University of Utah researchers.

The new work

Lead author Jeff Anderson notes the truth that some functions are lateralized, which means they are generally specialized to one hemisphere or the other. Language, for example, is typically found in the left hemisphere. Attention is generally found in the right.

But while some functions may reside in this way, it is a step too far to infer that we think with one side more than the other, or that this is somehow a determinant of personality.

It is as easy, for example, to infer the opposite, that our personality shapes how we think, and determines which side could be more dominant.

For this study researchers used the resting brain scans for more than 1,000 people, aged between seven and 29. Each person had lain in a scanner while their resting brain activity was analysed, a process which took about five to ten minutes.

This allowed the researchers to compare activity in one region with that in another. All up, the researchers divided the brain into 7,000 regions and then analyzed which regions were more lateralized, which means the activity was occurring in one hemisphere rather than both.

What seems more the case is that rather than having a thinking preference for one side or other, or for the brain to be dominated by one side or the other, most regions in the brain have connections to the other hemisphere.

In some of these, one side may outweigh the other, but that relates only to that region and its lateral connection, and not to the whole hemisphere. They found no relationship that suggests we choose or prefer to use the left-brain over the right, or vice versa.

Most of us are whole-brain thinkers, using different areas as we need

Researcher Jared Nielsen, a graduate student in neuroscience, says “If you have a connection that is strongly left-lateralized, it relates to other strongly lateralized connection only if both sets of connections have a brain region in common”.

So here’s the take home bit

We are constantly looking for ways to classify all kinds of things, including people, as this makes life easier.

In this case, we can’t use the left-brain/right-brain idea any more.

What we can do, is focus on those functions that could use a little more work, and build our efforts around those.

Impressive words to drop into the morning coffee chat

Optic chiasm, Longitudinal fissure

What do you think?

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About brendonbclark

Hi, I’m Brendon, but people usually call me B. I’ve a Masters degree in psychology, postgraduate qualification in mental health, and qualifications in counselling, professional supervision and adult education. I consult, speak and blog. Join me, you can subscribe for free.
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2 Responses to The myth of left brain vs right brain.

  1. Pingback: Left Brain, Right Brain - Creativity And Innovation | The Creative Mind

  2. Sharon King says:

    He is very cute!


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