Ancient Lefties: The History of Obama's Handedness

Heather Whipps, LiveScience's History columnist,

LiveScience.com

Something sinister is going on, and newly-inaugurated

President Obama is behind it.

From the Latin for left, "sinistra," southpaw Obama is

another notch for the column of left-handed presidents,

now totaling eight - a proportion (out of all 43 men who

have been POTUS) that is well above their representation

in the total population, which hovers around 10 percent.

(Let's count James A. Garfield as a lefty, although some

say he was ambidextrous and others say he was a lefty;

many ambis are lefties who learn to do some tasks with

their right hands.)

In fact, every president since 1974 with the exception of

Jimmy Carter and George W. Bush has been left-handed,

as is Obama's former Republican opponent Sen. John

McCain. Al Gore is too.

Is it just a coincidence, or is there something about being

left-handed that can make for a more presidential

demeanor?

Some evolutionary advantage, whether overall greater

intelligence or language skills, has kept a stable group of

lefties for at least the past 200,000 years, said Chris

McManus, professor of psychology and medical education

at University College London.

Left-handed tools chipped 500,000 years ago

There have been lefties for as long as there have

humans, historians agree.

Some of the oldest evidence of left-handedness comes

from Kenya, where of a 500,000 year-old cache of 54

stone tools made by one of our pre-human ancestors, six

(or about 11 percent) were chipped using the left hand.

Similarly, Neanderthals working with meat and stone tools

more than 150,000 years ago left marks on their teeth at

left and right angles - indicating opposite hand use - in

almost perfect proportion with today's 9:1 ratio.

Paleolithic cave paintings from France and Spain also hint

that lefties walked among our ancestors about 30,000

years ago. Studying a collection of so-called negative

hand drawings on the cave walls - similar to tracing one

hand with the other - scientists found that individuals drew

their left hand much more frequently than the right.  

The laundry list of lefties goes on through history, with

records telling us that a number of famous ancient figures

probably favored their southpaw as well, from Alexander

the Great to Charlemagne, Holy Roman emperor.

Though ancient sample sizes are small and poor

estimates of the exact proportion of lefties, the existence

of left-handedness is clear even hundreds of thousands of

years ago, McManus said.

Left tied to language

Despite its long history, left-handedness is a uniquely

human trait. Chimpanzees and gorillas, with whom we

share an ancestor and a number of common physical

attributes, don't seem to favor one hand over the other.

Instead, left-handedness may have developed along with

another characteristic known just to humans - language.

Most people process language in the left side of their

brain, the hemisphere that also controls the right side of

the body, and have done so presumably since humans

started chatting a few hundred thousand years ago.

Whichever gene made the left side of our brains 

responsible for language also played a role in making our 

right side dominant, experts such as McManus believe.

Though a specific left-handed gene has yet to be found,

the trait to choose one hand over the other is likely 

inherited, agree scientists. Left-handed parents are far

more likely to produce left-handed children, and those

children appear to begin favoring that hand in the womb,

according to a 2004 study on 10-week-old fetuses.

More recent research suggests that, while developing, the

two sides of the brain actually "fight" for specialized

control of certain functions, such as handedness, with the

left side (which controls the right - are you following?)

more often coming out on top.

Interestingly, even when the right side wins, the left brain

often shares some of the duties, studies have shown. So

while right-handed people usually process language

exclusively in the left side of their brain, lefties process

language mostly in the right but partly on the left as well.

That preferential wiring may make lefties more adept at

certain skills required for leadership according to

McManus, who wrote about his theories in his book "Right

Hand, Left Hand" (Harvard University Press; 2002).

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http://news.yahoo.com/s/livescience/20090129/sc_livescience/ancientleftiesthehistoryofobamashandedness;_ylt=AjL.92alMnqDnThcjjCiowEbr7sF

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