Governing from the left.

Today, only about one in 10 American males is left-handed, but when Barack Obama took the oath of office Tuesday by raising his non-preferred hand, he was the third southpaw among the last four presidents.

This should be no cause for concern for American righties. Indeed, it is likely that the small, left-handed minority - which perseveres against righteous prejudice, taboos, social pressures, and a hostile physical world - is better equipped to run the nation than right-handers.

Few people know more about left-handedness than Chris McManus, a professor of psychology and medical education at University College London. He says righties tend to be analytical, completing one task before moving on to the next; southpaws, on the other hand, are able to switch rapidly from one task to another.

McManus adds that that left-handers' brains are structured differently in a way that widens their range of abilities.

In his 2002 book

Right Hand, Left Hand

, McManus argues that left-handed people as a group have historically produced an above-average quota of high achievers. For one, Leonardo da Vinci painted the world's most famous smile with his left hand.

It took 88 years for America to elect its first known southpaw - James A. Garfield, who managed to sign a few bills with his left hand before being shot four months after his 1881 inauguration. It has been widely reported that Garfield, who died later that year, could simultaneously write in Greek with his left hand, Latin with his right; his biographer, Allan Peskin, says this is without foundation.

It would be 64 years before the second lefty occupied the White House - Harry S. Truman in 1945. Gerald R. Ford became No. 3 in 1974. Next came George H.W. Bush in 1989, then Bill Clinton in 1993, and now Barack Obama is lefty No. 6.

Some reports have tagged Herbert Hoover as a southpaw, but his presidential library says that he was right-handed and that any contrary belief was probably due to a reversed photograph.

Likewise, Ronald Reagan also is often miscast by some as a lefty. Reagan biographer Edmund Morris says that the 40th president might have begun life as a left-hander, but that he was soon converted by right-minded teachers. As an actor, Reagan used his right hand to throw a football as the Gipper; as chief executive, he used it to sign bills and hammer at the Berlin Wall.

In the first 155 years of the American presidency, a lefthander held the office a scant four months; in the next 63 years, southpaws held power for 22 years. If Obama serves two terms, left-handers will have occupied the White House nearly half the time since World War II.

This leftward trend is no coincidence. It reflects a slow acceptance of those who instinctively throw a ball, sign their name, or spoon their soup with their left hand.

In an e-mail interview, McManus estimated that only 3 percent of those born in 1900 were left-handed. Back then most natural lefties would have been forced to switch by parents and teachers. Moreover, there were probably fewer born lefties in the first place. "Left-handers would have been victimized and found it harder to find a partner, so [they] would have had fewer children," he said. The rising average age of motherhood, in his view, also might contribute - older women are more likely to bear left-handed children.

We don't know much about Garfield, but the next three lefty presidents all endured interference with their choice of hand. Truman biographers have written that teachers forced him to write with his right hand, which he did his entire life. But as president, he opened the baseball season by throwing out the ceremonial first ball left-handed (except in 1950, when he tossed out balls with each hand).

And we might safely assume that he stopped the buck with his left hand.

Gerald Ford's parents and early teachers forced him to use his right hand, according to his autobiography, but they eventually gave up. This confusion perhaps explains why he wrote with his left hand while seated, with his right hand while standing. George H.W. Bush's mother insisted that he play tennis right-handed.

Like Clinton, Obama experienced no such tempering, and he is described by his brother-in-law, Craig Robinson, as totally left-handed, whether he's hitting a nine-iron, rolling a gutter ball, executing a behind-the-back dribble, taking notes in a debate, or, now, signing bills and proclamations (while trying not to smear the ink with the hand that is following what he has just written).

Left-handedness remains a puzzle of science, with lots of tantalizing clues but no complete answers, and history has yet to prove or disprove McManus' hypothesis about the natural superiority of southpaws.

At this point the only certainty about Obama is that sitting next to him at state dinners might be challenging.

Known Lefthanders

In the Oval Office

Harry Truman

Gerald Ford

George H.W. Bush

Bill Clinton

Barack Obama

Herbert Hoover and

Ronald Reagan

also appear on some lists, but there is film evidence of Hoover writing with his right hand, and a biographer says Reagan may have been born lefthanded but was converted to righthanded by teachers.

The 44th president

would have been lefthanded even with a different election outcome, as

John McCain

is also a southpaw.

Some Other Lefties

In U.S. Public Life

, mayor of New York.

, former New Jersey senator.

, former presidential candidate.

, former vice president.

, former presidential candidate.

, former secretary of state.

, the late former vice president.

and

Anthony M. Kennedy

, Supreme Court justices.