8/24/16

 Of our last 15 presidents, these seven guys all have something in common. Do you know what it is?

If you guessed that they were all left-handed, you’re right!  Or, more accurately, non-right handed. That’s astonishing, as lefties account for only about 12.5% of the population (a little more for men, a little less for women) but 47% of our most recent presidents.

And it’s not just cherry picking recent presidents.  It’s quite possible that previous presidents, all the way back to George Washington, included lefties, but we’ll never know as left-handedness was strongly discouraged until quite recently. Left-handedness was previously thought to be tied to criminality, insanity and feeble-mindedness.  Sinister! 

Anyway, how did that presidents’ thing happen? Does America somehow prefer lefties? What makes people non-right handed? Are they more likely to die earlier?  And what about cultures where the use of the left hand is socially forbidden?

Let’s start with defining that whole handedness thing.  Actually, let’s not, as it turns out to be much more complicated than I thought.  Some people are pure lefties. Some are mixed lefties, like my dear husband, the Mac Geezer, who proposed this presidential question to me last week. He eats and writes with his left hand but plays sports with his right hand and uses a right-handed mouse for his Mac.  Some lefties are also left-eyed and left-footed but some not.  And some, like my 19 month-old granddaughter, are currently ambidextrous.  Notice the spoons in both hands.

What causes hand preference? 

The theory I like best suggests that there’s a dominant Right-Shift gene or allele.  Twenty-five percent of the population would have two of these R-S alleles.  They would be right handed. 50% of the population would have one but not both alleles.  They would still be right handed because it's dominant.  And the remaining 25% of the population wouldn’t have a Right-Shift gene. Pure chance would mean that half of those remaining 25% would be right handed and half would be left handed.  That would bring the non-right handed population to 12½ %, which is almost exactly where it lies. I like that! Doesn’t explain why men and gay people of both genders are more likely to be non-right handed. More work to do.

Are left-handed people more likely to die earlier than right-handed people.

 NO!  That result was bogus, based first on faulty conclusions by people who should have known better and then later on faulty research.  Don’t even get me going. You lefties are just as likely to live as long as the righties.

Does culture make a difference?

Some cultures frown heavily (understatement) on using the left hand to eat.  And not surprisingly, kids from those cultures are less likely to be non-right handed than other kids. That cultural preference even slopped over into a suppression of left-eyedness!

What else?  Bits and pieces:

 Deaf people are more than twice as likely to be left-handed as hearing people. That may be tied to delayed language acquisition during early childhood.

There’s a relationship between schizophrenia (delusions and hallucinations, not multiple personality) and atypical handedness. Atypical means hand preference shifts during the same task. Their relatives, too.

Forcing a child to switch from left hand to right hand does not cause stuttering.

Handedness is tied to eyedness but not footedness or earedness.

Now about those presidents:

I couldn’t find anything that looked really solid on why we keep electing left handed presidents. There were some suggestions that lefties have to be more flexible and inventive to survive in a right-handed world. I saw a suggestion that our society perceives lefties as more creative, so who knows.  What I do know is that both Hillary Clinton and Donald Trump are right handed. Rand Paul and Lindsay Graham are lefties. The rest of the primary candidates are all right handed, as is Ben Carson (lefties are discouraged from becoming surgeons).  Anyone know about Gary Johnson or Jill Stein?

Is political leaning tied to handedness?

No. But. People on the left and right coasts are more likely to be non-righthanded than those in the South and Midwest.  Make of that what you will.

And then there’s this:

“During the 2008 US presidential campaign, Barack Obama was faulted by Sarah Pain for signing bills with his left hand. Palin’s comments prompted conservative news reporters to urge Obama to learn to use his right hand to be like everyone else.” Personally, I think Palin was kidding, but you never know.

  

I based a lot of this on Clare Porch's 2015 book, Laterality: Exploring the Enigma of Left-Handedness.