[MD] Arlo

[ARLO JAMES BENSINGER JR]

[Ian]
... different people have different propensities to mental styles that use the different halves.

[Arlo]
No. The research says exactly otherwise.

[IG] Evidence - ready when you are.

[Arlo]
I've already listed two different overviews of the current research. Each of these has links to the empirical studies cited. But, sure, I'll play along...

http://www.npr.org/blogs/13.7/2013/12/02/248089436/the-truth-about-the-left-brain-right-brain-relationship
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0071275
http://ideas.time.com/2013/11/29/there-is-no-left-brainright-brain-divide/
http://www.livescience.com/39373-left-brain-right-brain-myth.html
http://www.sciencedaily.com/releases/2013/08/130814190513.htm
http://scan.oxfordjournals.org/content/8/4/475.abstract?sid=b99d03b9-38cc-4858-98e3-49f54244898d
http://www.spring.org.uk/2013/08/debunked-right-brain-and-left-brain-personalities.php
http://theness.com/neurologicablog/index.php/more-left-brain-right-brain-nonsense/
http://www.psychologytoday.com/blog/the-theory-cognitive-modes/201401/left-brain-right-brain-wrong
http://www.yalescientific.org/2012/04/left-brain-right-brain-an-outdated-argument/

"How, then, did the left-brained/right-brained theory take root? Experts suggest the myth dates back to the 1800s, when scientists discovered that an injury to one side of the brain caused a loss of specific abilities. The concept gained ground in the 1960s based on Nobel-prize-winning "split-brain" work by neuropsychologists Robert Sperry, and Michael Gazzaniga. The researchers conducted studies with patients who had undergone surgery to cut the corpus callosum – the band of neural fibers that connect the hemispheres – as a last-resort treatment for epilepsy. They discovered that when the two sides of the brain weren't able to communicate with each other, they responded differently to stimuli, indicating that the hemispheres have different functions.

Both of these bodies of research tout findings related to function; it was popular psychology enthusiasts who undoubtedly took this work a step further and pegged personality types to brain hemispheres.

According to Anderson:

The neuroscience community has never accepted the idea of 'left-dominant' or 'right-dominant' personality types. Lesion studies don't support it, and the truth is that it would be highly inefficient for one half of the brain to consistently be more active than the other.

Yet, despite Anderson's work and other studies that continue to disprove the idea that personality type is related to one or the other side of the brain being stronger, my guess is that the left-brained/right-brained vernacular isn't going away anytime soon. Human society is built around categories, classifications and generalizations, and there's something seductively simple about labeling yourself and others as either a logical left-brainer or a free-spirited right brainer."

"This is one of those memes that refuses to die. It’s a zombie-meme, the terminator of myths, one of those ideas of popular culture that everyone knows but is simply wrong – the idea that individuals can be categorized as either left-brain or right-brain in terms of their personality and the way they process information."

I have no doubt those whose profession depends on the 'brainedness' myth will go down with their sinking ship rather than follow the research. But, hey, Peirce talked about the strength of tenacity. But here's a grain of hope, maybe rather than turning this into a battle with me, you should really let this cast a little doubt on your beliefs.


Finally, I like how one author ends his article: The left-brain/right-brain dichotomy is pop-psychology pseudoscience. Be suspicious of anyone touting it as a legitimate or insightful way of looking at human personality or cognition."

Yep.

Finally, just to avoid the "there are differences!" reply, lateralization is universal, not personality-dependent. "For example, language function lateralizes to the dominant hemisphere, which is the left hemisphere for most people. Visuo-spacial reasoning lateralizes to the non-dominant hemisphere (right hemisphere for most people)." And again, even this can be overcome when necessary (neuroplasticity). 

At the very least, I hope anyone with half a brain will not put this idea that the "hemisphere dominance" myth maps on to Pirsig's notions of (SOM-derived) classical and romantic modes of thinking.