Have you ever heard people say that they tend to be more of a right-brained thinker or a left-brained thinker? From books to television shows you have most likely heard the phrase mentioned numerous times. Perhaps you've taken an online test to determine which type best describes you. I have, and it heightened my curiosity for how my brain works, and if the specific hemispheres within it determine my traits. In psychology, the left-brain, right-brain dominance theory in based on what is known as the lateralization of brain function. Lateralization of brain function means that there are certain mental processes that are mainly specialized to one of the brain's left or right hemispheres. For example, it has become common knowledge that in most people the left-brain is dominant for language. The right hemisphere, on the other hand, is involved more strongly in emotional processing and representing the mental states of others. However, the distinctions are not as clear-cut as the myth makes out. For instance, the right hemisphere is involved in processing some aspects of language, such as intonation and emphasis (Springer and Deutsch 2).
According to the theory of left-brain or right-brain dominance, formulated by Nobel Prize winner Roger W. Sperry in 1981, each side of the brain controls different types of thinking. Additionally, people are said to prefer one type of thinking to the other. For example, a person who is "left-brained" is often said to be more logical, analytical, and objective, while a person who is "right-brained" is best at expressive and creative tasks, and is said to be more intuitive, thoughtful, and subjective ("People being 'right-brained' or 'left-brained' myth debunked").
Sperry developed this theory while studying the effects of epilepsy. He discovered that cutting the corpus callosum- the structure that connects the two hemispheres of the brain- could reduce or eliminate seizure ("People being").