In today's Washington Post we have a piece on left-handed presidents. The next president will be left-handed, since Barack Obama and John McCain are both southpaws. Since 1945, 5 of 12 presidents have been left-handed: Truman, Ford, Reagan, Bush I, and Clinton. Since only 10 percent of the general population is left-handed, we wrote about whether there's something about the brains of left-handers that qualifies them for leadership. The answer is maybe - and in a way that may help explain Barack Obama's gift for language.
I posted a previous op-ed from the New York Times here on DailyKos, giving literature support for key scientific points. That piece was based on our book, Welcome To Your Brain. In this case the published article was condensed, partly to accommodate a picture of Ned Flanders's Leftorium. And now, a more detailed version...
The Southpaw President
by Sam Wang and Sandra Aamodt
As Barack Obama and John McCain debate this fall, attentive viewers may suspect that their television picture is reversed when they see both candidates taking notes with their left hands. This has happened once before. In 1992, southpaws George H.W. Bush, Bill Clinton, and H. Ross Perot debated three times on the same stage.
Since the end of World War II, six of twelve presidents have been left-handed: Truman, Ford, Reagan, Bush I, Clinton, and this year, either Obama or McCain. That seems like a lot, and it is: only one in 10 people in the general population is left-handed. Is there something special about left-handers?
For years, left-handedness was an object of suspicion, not a qualification for office. A right-hand man is indispensable, while dancers avoid a partner with two left feet. In the New Testament, sinners who do not meet with the Savior's approval go to His left—and to eternal damnation. "Adroitness" and "dexterity" derive from French and Latin words for "right," while "gauche" and "sinister" derive from words for "left." No wonder that well into the 20th century, children who showed signs of left-handedness when writing were forced to switch hands. Although this practice has faded in many developed countries, modern Japanese children are still compelled to use their right hands.
Even today, left-handers are thought to be accident-prone. This is a myth. No consistent differences between northpaws and southpaws have been seen in the rate of automobile or machine-shop accidents. Apprehension among many left-handers rose in 1991 when a U.S.-Canadian research team reported that left-handers died nine years earlier than right-handers, on average. The authors speculated the cause might be higher rates of accidents or disease. They received a hailstorm of criticism, including death threats.
The resulting attention did, however, uncover a fatal flaw in the team's methods: biased samples. (refutations: [1] [2] [3] [4]) Because naturally left-handed people were long discouraged from using their dominant hand, many older people whose innate tendencies would place them in the left-handed population were scored as being right-handed, and their deaths were recorded as "right-handed" deaths. This group could have included Ronald Reagan, who used his left hand for many everyday tasks but wrote with his right hand—and lived to 93. McCain supporters can take comfort that although, at age 72, he would be the oldest president ever inaugurated, he has the same chance of making it through his term in office as a right-hander of the same age – about seven-to-one in favor.
But is it possible that left-handed people—and presidents—think differently? Although on average, left-handers and right-handers are no different in academic achievements and other performance indicators, a subpopulation of southpaws perform exceptionally well, perhaps because of how they arrived at their handedness. These left-handers may be better armed (in a literal sense) for the challenges of leadership. Their advantage may come from how they arrived at their habit.
Left-handers have been suggested to come by their orientation by three different routes. In one group are people who would have become right-handed, but early in development suffered some injury to the left side of the brain – the side that controls the right side of the body. They compensate by using the intact side of the brain, accounting for the observation that southpaws have an unusually high rate of neurological disorders. We would guess that presidents are not very likely to come from this category. In a second group are people whose brain development occurs normally, except that all brain functions are in the opposite hemisphere than in most people. These people express handedness – and other typically left-brain functions, such as language – in the right hemisphere. Imaging studies of brain activity suggest that about one in ten left-handers falls into this category. However, there may be nothing remarkable about their brains, other than being mirror images of other brains.
The third category is special. These are people whose innate language capacity and handedness are both initially localized to the left hemisphere, the usual arrangment for nearly all right-handers. But then, early in life, they begin to use the left hand more often than the right. Using the left hand early in life may somehow allow both sides of the brain to handle language. Brain imaging studies have shown that 1 left-hander out of 7 processes language on both sides of the brain. Both-sided language processing is much less common (1 in 20) in right-handers. A balanced arrangement may provide more brain space for language. Indeed, left-handers are overrepresented among high scorers on the Scholastic Aptitude Test. Legendary speakers such as Obama, Reagan and Clinton may have their handedness to thank for their gift.
The benefits are not only verbal. Left-handers—Pablo Picasso and Benjamin Franklin, for instance—are common among artists and great political thinkers. Many lefties also have unusual mathematical skills. And on problem-solving tests, left-handers are more likely to find unexpected or counterintuitive solutions.
So maybe it's not surprising that left-handers are overrepresented in one of the fiercest competitions of all, the race for the White House. But why did southpaws start popping up in the past 50 years? Perhaps before then, few overcame the pressure to be right-handed. Of only two reported left-handers among 51 British prime ministers, one was the famously stubborn Winston Churchill, whose contrary nature appeared early in life. The only known left-handed president before the 20th century was the ambidextrous James Garfield, who could simultaneously write the same sentence in Latin with one hand and in Greek with the other. Talk about a way with words.
Should we add left-handedness to the requirements for U.S. presidents? The first President Bush was a lefty but was "born with a silver foot in his mouth," as the late Ann Richards so famously put it. As two right-handed scientists, we recommend a dose of...evenhandedness.
Sam Wang is an associate professor of molecular biology and neuroscience at Princeton University. Sandra Aamodt is the editor in chief of Nature Neuroscience. They are the authors of Welcome to Your Brain: Why You Lose Your Car Keys but Never Forget How to Drive and Other Puzzles of Everyday Life.