February 2, 2009

what the left hand is doing

Some facts about left-handedness.

1. 8 of the 44 presidents have been left-handed. Almost double the incidence of left-handedness in the general population.

2. Favoring a particular hand is unique to humans. Neither chimps nor gorillas favor a hand.

3. The incidence of left-handedness seems to be constant throughout history.

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.

4. Whereas language is usually processed in the left-hemisphere for right-handed people and in the right-hemisphere for left-handed people, left-handed people also process some language in the left-hemisphere — providing for the possibility that some sort of evolutionary advantage exists for lefties.

comments

  1. Cooper Renner on February 2nd, 2009 at 11:09 am

    Them over-achieving lefties!

  2. Carl on February 2nd, 2009 at 3:13 pm

    Yes, we’re here to rule the world. Which is maybe why cultures around the world have persecuted lefties throughout history. :-) In fact, I remember growing up in the early 80s, my kindergarten teacher would hit my hand whenever I started to write with my left hand! She continued until my dad finally told her to stop.

    My extended family is definitely weird, every single family has at least 2 lefties 66-100% lefty per family rate.

  3. Andrew Simone on February 2nd, 2009 at 3:50 pm

    Deron, you have to stop providing me with excuses to believe that the world hasn’t recognized my genius yet.

  4. Elizabeth Perry on February 2nd, 2009 at 8:19 pm

    Beyond Andrew, how many other flockers/commenters are left-handed? More than one in ten? (And I’m left-handed, so that’s two of us unrecognized so far…) Anyone ambidextrous?

  5. Deron Bauman on February 2nd, 2009 at 8:38 pm

    because of a climbing injury in my twenties and this latest run in I have developed some ambidexterity, but it definitely didn’t occur naturally.

  6. Cindy Scroggins on February 3rd, 2009 at 9:17 am

    I’m passably ambidextrous. My writing with my left hand isn’t as clear as with my right, but I suppose it would become so with practice. I find myself doing a lot of things with my left hand without thinking about it. And I can write in mirror image as easily as I can write “right.” I’ve got a whole left brain/right brain mash-up going on.