What do Lady Gaga, Queen Victoria, Michelangelo and President Obama all have in common? Whether signing a bill into law or painting a masterpiece, they all do it southpaw style. Throughout the ages, lefties have made up a consistent 10 percent of the population, but the reasons behind this minority dexterity remain shrouded in mystery.  In his new book “The Puzzle of Left-handedness,” author Rik Smits attempts to shed a little light on this mystery, cataloging the lore, science, and historical “whiff of negativity” surrounding left-handedness.

Historically, left-handedness has been associated with all manner of evil and malady — mental retardation to cancer to criminality and working for the devil. In more recent times, however, some psychologists have postulated that being left-handed is a sign of a strong right brain, and the language skills and creativity that are associated with this hemisphere. This is the argument made by University College London psychologist Chris McManus in his book “Right-Hand, Left-Hand.”   He also says that throughout history, lefties have made up a larger proportion of high achievers than would be expected given their minority status.

A look at the long list of celebrities, politicians, and historical figures that are southpaw seems to support McManus’  theory. After all, five out of the past seven U.S. presidents were lefties (George W. Bush and Jimmy Carter were not).  Many cultural icons of our day are lefties as well: Oprah, Gaga  and Mark Zuckerberg, to name a few.

But is there anything inherently special about lefites?

We know that they may be genetically different because a child is twice as likely to be left-handed if one of his parents is and four times as likely if both parents are lefties.  Other theories explaining left-handedness mention disturbances in hormones or slight brain damage while a child is still in the womb.  Smits offers yet another theory in his book: Lefties derive from identical twins.  Because identical twins can sometimes have mirror traits, he postulates that lefties arise when an embryo splits in the womb, leaving one twin righty and the other lefty.

The fact that twins are twice as likely to be lefty as nontwins offers some support to Smits theory, but his ideas have never been scientifically tested.

For all their mythology, lefties are probably not some form of supertalented genetic mutant, Smits concludes:   “Most left-handers are just left-handed, nothing more,” he writes.