There are aspects of truth in the theory of left and right brain cognition. The brain clearly has two hemispheres. The hemispheres are joined through a tract of connective tissues called the corpus callosum. Some activities trigger activity in specific areas of the brain. The idea behind the left brain and right brain theory is that people are naturally inclined to use one hemisphere of the brain. This is called lateralization or hemispheric specialization.

Roger Sperry, a neuropsychologist, studied brain activity in the bilateral brain hemispheres in 1960. He analyzed the behaviors of people with severed nerves between the hemispheres of their brains. The nerves were severed as a treatment for their epilepsy. Sperry believed that the people participating in his study must have brain hemispheres that operated independently because there was no communication between sides. Sperry made great progress in understanding how the brain works, but he did not develop left brain-right brain theory. Other people used Sperry's research to fabricate a pop-culture theory.

People with a dominant left brain hemisphere display aptitude for linguistics, logic, strategic thinking, and ability to recall information. They usually enjoy math and science, and they have strong critical thinking skills. Other characteristics associated with the left side of the brain are a tendency to be realistic and practical, and a preference for long-term planning.

People with a dominant right hemisphere of the brain tend to be imaginative, idealistic, and creative. They are likely to have random thoughts and enjoy music and art. Intuition and heightened ability to recognize faces are also associated with right-brain thinking. Those with right-brain dominance are frequently joyful and express appreciation. They are not shy about expressing emotions and often have very strong beliefs.

Proponents of the left-brain, right-brain theory claim that understanding which half of the brain is dominant helps people learn and process information efficiently. It is also supposed to grant insight into personal feelings and thoughts. Unfortunately, belief in the left-brain, right-brain theory can be detrimental too. Claiming a dominant side of the brain easily leads to automatic and inaccurate assumptions towards individuals skill and ability.

The left-brain, right-brain theory is referred to as a neuro-myth in some scientific circles. Multiple studies have found that people just don't think with one side of the brain more than the other side. Multiple areas of the brain are active during different activities, and sometimes active areas are all on one side. The areas of activity are the same for everyone. There is no significant difference between individuals related to activity in a specific brain hemisphere.

The myth isn't just harmless fun. A student experiencing frustration in certain subjects may give up entirely because of a belief that skill is predetermined as right-brained or left-brained. A personality quiz online can cause people to doubt their own abilities. An underlying belief that a person has certain skills related to brain hemispheres can undermine attempts to learn new skills. The self-doubt and subconscious pre-determined conclusions cause a self-fulfilling prophecy. A dominant brain hemisphere does not prevent understanding of any concept, but the effects of believing right-brain left-brain theory prevent a person from learning certain skills.

Specific areas of the brain are associated with an activity such as movement and vision. The left side of the brain controls the right side of the body and vice versa. The left temporal lobes of the brain are important for understanding language, although many areas of the brain are active in association with language. Emotional context of language is associating with the right hemisphere of the brain. Sperry's research did find that the left side of the brain is associated with analytical skills, while the right half is responsible for spatial perception.

The left brain-right brain myth seems determined to hang around no matter how many times it is debunked. Most people should be able to see the myth for what it is just from their own observations. Human ability and skill is not divided between analytical or creative. Computer programmers are sometimes artists too. Writers who ultimately end up on the bestseller lists come from all sorts of backgrounds and professions. Extensive logic and reasoning skills do not nullify emotions or strong beliefs. Humans have an amazing ability to perform well and show aptitude for a wide variety of concepts and skills.