Right And Left Brain Personality Theory Debunked

The human brain is organized in a manner identical to that of other mammals. However, it is considerably larger in size. The brain can be described as being divided into left and right cerebral hemispheres, which individually are often referred to as ‘right and left brain.’ The two hemispheres are connected by an intricate network of nerve fibers called the corpus callosum.

This is process is known as lateralization.

Anatomical organization of the brain

Anatomically, the left hemisphere is considered as the “logical brain” and is responsible for wording, logical thinking, analysis, linearity and sequence. The left brain also controls the right side of the body.

In contrast, the right hemisphere controls the left side of the body and is known as the “creative brain”. The right hemisphere is the part of brain that deals with imagination and colors, spatial awareness, as well as rhythm.

This myth originated in the 1800s, following several scientific researches that demonstrated that severing one side of the brain could lead to a loss of specific abilities. The myth gained ground in the 1960s and might have arisen from Roger Sperry’s Nobel Prize winning research; with his study of epilepsy patients following a brain surgery. The study revealed that damaging the corpus callosum, the connection between the two brain hemispheres could result in a loss of communication between the two sides of the brain. 

For instance, when one patient was asked what he wanted to do, his left brain responded with “draftsman” but his right brain responded with “automobile racer.”

"Right" and "left" brainers: myth or reality?

The neuroscience community never bought into this notion. Today, thanks to the evolution in technology and medical research, physicians and scientists are better able to understand the functioning of the brain. According to the neuroscientists at the University of Utah, the theory that ‘right brainers’ are more creative and thoughtful and the ‘left brainers’ are more logical and detail-oriented is absolutely inaccurate.

Researchers have done much to debunk this idea. Over a period of two years, researchers examined the functional Magnetic Resonance Imaging (MRI) scans of 1,011 people within the ages of seven and twenty-nine from a database called the International Neuroimaging Data-Sharing Initiative (INDI). Each subject was asked to lie in the scanner, thinking about nothing in particular for 5 to 10 minutes, and their brain activity was recorded and analyzed for evidence of increased activity in either the left or right sides of the brain.

In total, 7,266 distinct regions of the brain were identified and researchers examined the areas that were the most lateralized. In lateralization, certain mental processes are specifically attributed either to the right side, or to the main side of the brain. Functional lateralization of these regions in each participant’s brain was studied and no evidence was found that individuals preferentially use their left brain or right brain network more often than the other. Dr. Jeff Anderson, the lead author of the study stated: 

Brain Lateralization And Gender differences

The researchers also investigated the effects of gender on lateralization and how lateralization changes with physiological development between the ages of 7 and 29. It was shown that differences in gender didn’t significantly affect brain lateralization. However, the results of that research truly contradict the results obtained in prior experiments, in which gender differences were shown to play a tremendous role in brain connectivity. This may be due to Differing methods between the two studies.

Jared Nielsen, a graduate student in neuroscience who carried out the study as part of his coursework made the following statement: “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. Everyone should understand the personality types associated with the terminology ‘left-brained’ and ‘right-brained’ and how they relate to him or her personally; however, we just do not see patterns where the whole left-brain network is more connected or the whole right-brain network is more connected in some people.

Read More: Female vs. Male Brain – Is There A Difference?

In other words, it is not accurate to say that creative people are more ‘right –brained’. It is not their over active right brain that is making them more creative, but rather, their entire brain. This finding reinforces the fact that some brain functions could be shifted more toward one hemisphere. 

Another important point: in the early 19^th century, certain scientists and authors believed that the shape of the skull could be read for moral and intellectual features. For example, the faculty of ‘philoprogenitiveness’ from the Greek for ‘love of offspring’, was located centrally at the back of the head. They coined this as ‘phrenology’, a concept related to physiognomy, in which it is said that one’s face is the perfect window to his/her character and personality. However, this idea is discredited by some common discrepancies in real life, such as criminals having an “attractive” and “trustworthy” face (example of the notorious serial killer Ted Bundy).

More studies need to be done to establish the relationship between behavior and lateralized connectivity, but so far researchers have demonstrated the left and right lateralized networks are stronger among a constellation of hubs in the left and right hemispheres. However, such connections do not allow us to favor one network over the other.