leftyFour out of five of our last presidents were left-handers.

Researcher Marian Annett hypothesizes that there is a gene for being right-handed and a gene for being nonhanded or random-handed. One could also say that most random-handed people have no gene for being right-handed. Studies vary, but most cultures show around 10% left-handers.

By Annett’s calculations, about 18.5% of modern populations retain this random-handedness proclivity, with about half of those displaying left-handedness and about half being right-handed. Various degrees of ambidexterity are mixed in.

Random-handedness is genetically inherited, usually revealing close relatives with that same feature. Various social and biological interventions can mask these relationships. My sister was left-handed, broke her arm in grammar school, and ended up writing with her right. Older folks were often instructed to write with their right hand regardless of their natural inclinations. This instruction was common in Catholic schools. Early brain damage or uterine trauma can compel a person to switch hemisphere and, for example, rely upon the left hemisphere for language instead of the right or both, making them left-handed. These folks are not genetically random-handed.

Among the many prejudices and divisive beliefs we’ve been giving up over the two hundred years is the disparagement of left-handers. These biases have built into our language what with sinister, sinistral and the Left being closely associated. In some cultures, one only wipes one’s butt with the left hand.

The random-handed are unique. They display an older genotype and are perhaps the bridge to understanding autism and conditions characterized by maturational delay. Still, they are not easily pigeon-holed, and they often display both remarkable physical and verbal prowess and sometimes impairments in the same areas. Presidents and stutterers are often left-handed.

Recent studies suggest dramatic increases in autism. If autism and left handedness are connected, have there been recent increases in left handedness?

The random-handed offer clues to both our evolutionary origins and our society’s future path. With another possible left-handed president, perhaps it’s time we explored this once vilified, re-emerging class.

Proceed to author’s FREE book download on this subject (The book is called Evolution, Autism and Social Change). 10 minute introductory video here.

on 10/8/09 in featured, Society | 1 Comment | Read More

Comments (1)


  1. Jon says:

    The dramatic increases in autism are due to changes in diagnostic criteria and a greater understanding of the condition.
    Lefthandness on the otherhand is much easier to diagnose so it is highly unlikely that rates of lefthandedness have increased!

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