By Don Lincoln, Ph.D., Fermi National Accelerator Laboratory (Fermilab)
There is a fascinating myth in modern culture of people being right-brained or left-brained. There is indeed a grain of truth to this myth; for example, the brain really does have two hemispheres, one left and one right. But, like many misconceptions in life, when it is studied, it unravels pretty quickly.
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Historical and Religious Views of Humanity
Humans are an introspective species, one might even say self-absorbed. It has long been believed that humanity is effectively at the center of the universe, whether because of the early geocentric ideas of Ptolemy or simply because humans are thought better than other species. It is an idea that even enters into some religions.
The Christian Bible does say that humans were to “have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over the Earth, and over every creeping thing that creepeth upon the Earth.”
Scientific View of Humanity
Modern science has a more prosaic, although no less extraordinary, view of humanity, properly placing homo sapiens as a single unique twig on the vast tree of life. It is ‘unique’ for a reason. For all the connections to the rest of life on the planet, there is no doubting human uniqueness. For humans alone have looked to the sky and wondered about their place in the cosmos.
Humans alone have thought about thought. And, taking humans down a peg or two, humans alone have worried whether these pants have made their butt look big or whether anyone could tell that they were wearing a toupee.
Although these thoughts are not always grand and noble, they are thoughts. The ability to think in highly complex ways is what distinguishes humans from other species.
Learn more about getting smarter about intelligence.
The Myth of Left-Brained and Right-Brained People
Perhaps, this is why there is this fascinating and recurring myth in modern culture about people being right-brained or left-brained. There is indeed a grain of truth to this myth, for example, the brain really does have two hemispheres, one left and one right. So, that part is indeed correct. But, like many things in life, when brain function is studied, it becomes complicated very quickly.
Scientists have known for many decades that the brain isn’t monolithic and that different parts of the brain have different purposes. The earliest reported data was in the 1800s when brain scientists took note of the fact that different types of brain trauma led to different yet specific loss of abilities. For instance, spatial abilities seemed to reside more in the right side of the brain, while language, for example, seemed to be preferentially located in the left.
This is a transcript from the video series Understanding the Misconceptions of Science. Watch it now, Wondrium.
The Origin of the Left-Brain Right-Brain Myth
In the 1960s, these initial observations exploded both into the scientific literature and in the public sphere when some impressive (and, frankly, scary) experiments were performed. It was during this decade that researchers including Roger Sperry and Michael Gazzaniga were experimenting to find ways to treat severe epilepsy.
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There was a class of patients whose seizures resisted treatments like psychotherapy and psychotherapeutic drugs. No matter the treatment, these people would have frequent and debilitating seizures. It was no way to live.
Gazzaniga and Sperry and others explored additional treatments. One treatment was to sever the part of the brain that connected the right and left hemispheres. That part of the body that connects the two sides of a healthy brain is called the corpus callosum. In these surgeries, surgeons simply cut the corpus callosum, turning what was once a single operating brain essentially into two separate ones. The whole prospect may have given others the creeps, but the surgeons had some success in treating epilepsy, so surgeries were performed.
It was from studies like this that scientists became aware of some of the regional differences present in the functioning of the brain. In fact, there is an absolutely fascinating body of scientific work done by studying these split-brain individuals. Actually, the study of how specific brain damage affects the abilities of individuals is incredibly interesting.
In any event, these studies found differences in the left and right side of the brain. Popularizers, marketers, and others grabbed onto these very early studies and ran with them. Society was told that the left brain is the analytical, logical, verbal half while the right brain is the creative, emotional, visual, and spatial half.
Learn more about how statistics can lie to you.
Checking the Veracity of the Left-Brained, Right-Brained Claim
Taking this to the next step, people were told that if they were dispassionate and cerebral scientific whizzes, they used the left side of the brain, while the artsy, creative, caring people used the right side of the brain. It was just too easy an explanation. People are rarely so dichotomous, that is to say, thinking versus feeling. It is really quite peculiar. It is not at all difficult to imagine that a scientist would be sad when his kitten unexpectedly died. Nor is it so difficult to imagine a singer being a shrewd businessman or woman. The world is not either/or.
So, what is correct? Well, it is true that there are right- and left-brain differences. The biggest is, of course, that the left side of the brain controls the right side of the body and vice versa. That one is considered a no-brainer.
There is also handedness, meaning being left-handed or right-handed. That seems to arise in individual differences in the right and left brain and the development of the fine muscle control centers of the hand. But what is being considered is more about thinking and where that originates in the brain rather than such ordinary things as muscle control. And the reality is that thinking occurs all over the brain.
There is some defensible merit in bits of the left-/right-brain ideas. For instance, language processing, once believed to reside only in the left hemisphere, is now understood to take place in both: the left side processes grammar and pronunciation while the right processes intonation.
Similarly, experiments have shown that the right hemisphere is not only responsible for spatial ability: the right hemisphere seems to deal with a general sense of space, while the left hemisphere deals with objects in specific locations. And it is relatively recent, with modern imaging techniques, that scientists can watch thoughts develop in real-time.
For instance, people can be shown pleasant or disturbing images and be asked to press one button for disturbing and another for pleasant. While this is happening, the activity of the brain can be monitored. To disentangle the individual components, researchers can simply present test patients with the images, but not require pushing a button. Or, conversely, the test subjects can push the buttons without seeing the images.
With studies like this, it is clear that the whole right-/left-brain idea is not real, at least not in the way that is often portrayed in the media and some classrooms.
Common Questions about the Mystery of Left-Brain and Right-Brain
Q: Can someone be left-brained and right-brained?
No, according to the research conducted with brain imaging technology there’s no reason to believe that individuals can be left-brained or right-brained.
Q: What is a left-brain person like?
According to the common hypothesis, left-brained people are believed to be more analytical and methodical in their thinking.
Q: What are right-brain thinkers good at?
As per the common hypothesis, right-brained people are believed to be more creative, emotional, and intuitive.
Q: Is there a dominant side of the brain?
Despite human nature and behaviors, there is no reason to believe that the domination of one side of the brain is the reason behind someone’s personality traits.