---

Handedness
Broadcast starting week of March 5, 2008

What do Leonardo da Vinci, Oprah Winfrey, and The Infinite Mind's host all have in common? They're all left-handed. This show explores what handedness reveals about how the brain works. Boxers Mike Smith and Christina Beccles from Gleason's Boxing Gym reflect on why it is that "southpaws are like a plague in boxing." Dr. Stanley Coren, Professor of Psychology at the University of British Columbia, discusses pathological left-handedness and what he calls "the left-handed syndrome." Dr. Daniel Geschwind, Director of Neurogenetics at the University of California, Los Angeles, explores the link between handedness and language. Richard Lederer, a.k.a. "Attila the Hun," comments on "when you're right, you're right" and other gauche assumptions. And Dr. Stephen Christman, Professor of Psychology at the University of Toledo in Ohio, talks about why what hand you rely on may be less significant than how strongly you rely on it... and the surprising links between handedness and memory.

"Handedness" begins with a personal essay by host Dr. Fred Goodwin. While he's naturally left-handed, he tells us, when he reached his school years, his teachers encouraged him and his twin brother to use their right, "or proper," hands to write. In short, they bumped into what Dr. Goodwin terms "a vast right hand conspiracy." The young Fred Goodwin soon learned to write with his right hand. Years later, he says, "I do admit to speculating that my adaptive ambidexterity means that my logical, linear, verbal left brain more easily communicates with my holistic, creative right brain. I'd like to think that a greater left-right connectedness can make it easier to convert right brain creativity into left brain productivity. But lets hear what the experts have to say…"

Next, we visit Gleason's Boxing Gym, in Brooklyn, where boxing champions Mohammed Ali, Riddick Bowe, and many others have trained. Here, trainer Mike Smith and boxer Christina Beccles talk about southpaw boxers and the element of surprise. "Nobody want to fight a southpaw in boxing, it's like a plague," says Smith. "When I take them out to fights, like the Golden Gloves, I never let them warm up in a southpaw position. Then when he gets in the ring, the trainer and everyone's like 'Oh my god, he's a southpaw!'" He laughs. "Boxing's a bunch of trickery." Christina Beccles, who trains at Gleason's, started off fighting "orthodox," but learned to fight southpaw and now confuses opponents with her ability to switch stances in the ring, or "switch hit." Says Smith, "Switch hitting… that's like the devil himself. Even to another southpaw it's difficult."

To learn more about Gleason's Boxing Gym, click here. To contact Mike Smith, write to Gleason's Boxing Gym, 73 Front Street, Brooklyn, New York 11201.

Is left-handedness pathological? In Dr. Goodwin's first interview on this show, Dr. Stanley Coren, author of The Left-Hander Syndrome, says about half of all left-handers are pathologically left-handed. According to Coren, "We believe that everyone was designed to be right-handed and that problems during pregnancy or delivery make someone left-handed. And these same problems can cause other problems." Some have linked left handedness with unusual levels of testosterone during pregnancy. Coren says such problems account for the high rates among left handers of immune system disorders ranging from allergies to thyroid disorders. Prominent lefties with immune system problems include President George Bush, who has Grave's disease, and President Bill Clinton, who has many allergies. Dr. Coren has also found data suggesting that left-handers are five times as likely to die of accidents as right handers. Left-handers are also more likely to be dyslexic, schizophrenic, alcoholic, and delinquent.

Dr. Goodwin then takes a call from Florida. The caller, Susan, asks whether her Crohn's Disease could be linked to her left-handedness. Dr. Coren tells her that there is a link, as with other immune related problems. Another caller, Phil, from Vermont, asks about whether there is such a thing as true ambidexterity. According to Dr. Coren, people who can do things equally well with both hands comprise only about one percent of the population. There may actually be an evolutionary disadvantage to ambidexterity, says Coren. Studies have shown that when a very quick manual response is called for, ambidextrous people are more likely to hesitate, if just for a fraction of a second, as though choosing which hand to use. Coren says there may be a link between left-handedness and spatial abilities, and points out that many lefties fit the profile as divergent thinkers, with very "quirky" minds, for example author Lewis Carroll, Muppets creator Jim Henson, and director and actor Charlie Chaplin.

To reach Dr. Stanley Coren, send him an e-mail. His website is www.stanleycoren.com

To order Dr. Stanley Coren's book, The Left-hander Syndrome, click here.

After a short break, Dr. Goodwin interviews Dr. Daniel Geschwind, Director of Neurogenetics at the University of California, Los Angeles. Which hand you rely on for writing and other fine motor activities is a window onto your brain, says Dr. Geschwind, particularly how your brain processes language. Most right handed people process language primarily in their left brains. Among lefties, on the other hand, about half use both sides of the brain to process language and ten percent process language primarily in their right brains. Because of the broader distribution of language in the brain, if a lefty loses the use of his right brain in a stroke, he is more likely to recover the use of language than his right-handed counterpart. While lefties are more likely to have some language processing difficulties, including dyslexia and stuttering, it may be that left handed people's different brain organization allow unusual development of other skills, such as spatial attention, and building mental maps and rotations.

There seems to be a major human gene that caused the shift of language to the right hemisphere and right-handedness. What we see in humans is a strong distribution - about 90 percent of the population is right handed, therefore more dependent on their left brains. Coupled with the lateralization of language in the left hemisphere, says Dr. Geschwind, this suggests that there's some fundamental link between our development of handedness and language. Some chimps may have slight right hand bias, but other animals are equally likely to prefer a left or a right paw. "In other words," suggests Dr. Goodwin, "As you get closer to the species with language skills you get closer to a likelihood to be right-handed."

To reach Dr. Daniel Geschwind write to Reed Neurological Research Center, Rm B-105 710 Westwood Plaza, Los Angeles, CA 90095 (310) 794-7537.

Next, The Infinite Mind's Emily Fisher interviews linguist and author Dr. Richard Lederer, the co-host of public radio's "A Way with Words," produced by San Diego's KPBS. "We make metaphors out of things that are close to us and that we value. With the hand we have both," he points out. Lederer explores linguistic associations with left-handedness and right-handedness. "If you look at the history of 'right,' he says, "You'll see it first was associated with 'right' as in rectitude… Hundreds of years later it became associated with the right side of body, hence 'right hand man', 'right hand of God.'" The left, on the other hand, has long had associations with the sinister (from the Latin for 'left'). Take the words "gauche," from the French for 'left,' and "gawky," derived from "gauche." And "When someone is awkward on the dance floor," points out Lederer, "We say he has two left feet. If you had two right feet you'd be just as awkward, though we never say that, do we?" In short, " It's not only door knobs and musical instruments that libel the left-handed, it seems to be the language itself."

Tp learn more about the radio show, "A Way With Words" click here. To contact Richard Lederer, go to his website: http://www.verbivore.com/.

Click here to order Richard Lederer's books, which include Anguished English and Merriam-Webster's Wordplay Crosswords.

If you're left handed or have a relative whose left handed, do you have a better chance of remembering what you did on your tenth birthday? Yes, according to psychologist Dr. Stephen Christman of the University of Toledo in Ohio, who studies the connections between handedness and memory. Episodic memory relies on both sides of the brain, which left-handed people are more likely to draw on equitably. This may be, he says, because most people who seem to be left-handed are really "mixed-handed." People who are purely left-handed are rare, he says. In one experiment, left-handed people and people with a left-handed parent or sibling did better at recalling events than right-handed people from right-handed families. That's because right handers with a left-handed sibling or parent are probably also mixed handed, he says, and became right handed by environmental accident. The use of both sides of brains seems to improve episodic memory. On the other hand, right-handed people from right-handed families have superior semantic memories.

People who rely predominantly on brain hemisphere over the other can stimulate the use of both hemispheres, and hence boost their episodic memory, through rapid eye movements between left and right. Moving your eyes to the right activates your left brain hemisphere; moving them to the right activates your right hemisphere. Some therapists have used this technique to help people with Post Traumatic Stress Disorder to recall memories. Clenching your right and left fists in alternation can produce the same effect.

To reach Dr. Stephen Christman, write to Department of Psychology, 2801 West Bancroft Ave, University of Toledo, Toledo, Ohio, 43606 or visit his web site.

Concluding the show, commentator John Hockenberry compares handedness to "the barely visible seam on a clear plastic globe." This asymmetry, says Hockenberry, is a barely visible flaw in a bodies that seem so very symmetric, a tell-tale sign of the complexity of the brain and mind.

· Back to the The Infinite Mind Index