Saturday, April 26, 2008

Left handed, right handed, both?

Ambrose Bierce


"Ambidextrous, adj.: Able to pick with equal skill a right-hand pocket or a left."

Ambrose Bierce

Total Man: An Evolutionary Theory of Personality, by Stan Gooch:

Early man, certainly agrarian man, could be tolerant of left-handedness or ambidexterity. Even as hunters left-handers would possibly be socially acceptable, However, there would probably tend to be more fatal accidents amongst them in the course of hunting, so that already there would be a tendency for the incidence of left-handedness to reduce in the general population. But under conditions of severe competition or in war two things would happen: (a) “consistently” more left-handers would be killed in battle and therefore gradually ‘bred out’ and (b) left-handers would be “perceived” to be less effective fighters.

Applied to human beings, this proposal receives strong support from two additional considerations: (1) the heart is biased to the left of centre, i.e. in the rearward and hense most protected position when the right hand is in actual use and (2) by reason of the crossing of motor and sensory fibbers to the opposite hemisphere of the cerebrum the dominate hemisphere is therefore “also” to the rearward and in the most protected position when the right hand is in use.

Does it make any difference whether one is left-handed, right-handed, ambidextrous--right or left foot dominate or right or left eye dominate? Perhaps a quirk of nature. In any case things can be performed with alacrity and deft skill in any case, granting ambidexterity having the edge. How bizarre to discover that there is a positive correlation between "left-handed" people and the sciences [including physics]. Would there be a cultural community of people developed [as one of several criteria] whereby left-handed people only did science. Is such a situation true in all case? What about those that retired the left hand usage and switched to right-handedness? Or those that are ambidextrous? One would certainly not draw the conclusion that such a situation is categorical for if a right-handed person lost the use of that appendage and was forced to use the left arm that would not necessarily means a sudden interest in science or excel in math. For me, I was left-handed until six or seven and switched. The world did little to accommodate left-handed children then. In the long run such a correlation would be like saying that there is a relationship between scientists and scientists having a fondness for peanut butter or oatmeal. It is interesting though. It may well have something due to the physical structure and activity of the brain.

There is quite a bit of history involving the dominance of one hand over the other. Through out history the stance and social significance of a dominating hand is interesting for there has been not to long ago a stigma placed on left-handedness and a long, long time ago there was a premium placed on left-handedness. It is interesting to note that all primates except man are ambidextrous, namely orangutans, chimpanzees, and apes will use either hand while man is the only one making a selection. Many very early forms of writing were written left-handed, reading from right to left. And it wasn't until Greek times did things switch the other way. A curious illustration is in early cave paintings where figures were facing right indicating a left-handed artist. Warfare would favor, in situations of one-on-one combat, a right-handed person inflicting wounds/death while the left hand was busy protecting a vital organ--the heart. Mortality among left-handed warriors must have been high and were soon converted or put in charge of logistics or to become scribes. Data for correlations of dominate hands [or eyes or feet] to science oriented people are zip and subject to much speculation. The unlucky to lucky position of hand dominance will probably shift again and again. Interesting to note that Beethoven, Goethe, Michaelangelo were left-handed and that I doubt that gender plays any significant role.

The ambidextrous feature is interesting and I have read some rather unusual hypotheses regarding why there is favoritism of left or right-handedness. It is believed that all humans are born ambidextrous and through sociological favoritism [a cultural posture fostered by popular determinism], human sense of balance [the human body may be off centered favoring a particular stance], brain functions, external physical forces--who knows why. Told ya, some of the above are bizarre. Interesting to note that the majority of animals are ambidextrous though some species [certain primates] may favor the right hand. It probably doesn't matter much to the squirrel gathering fall’s fruit of black walnuts--they can snatch the nut with either paw with alacrity. However, it may well be advantageous for humans to be ambidextrous. Sometimes, certain situations may require a clever non-dominate hand for assistance.


Timray said...

An interesting aspect of this is our educational systems bias. I have heard more than once from student of public and private elementary schools of teachers forcing "south paws" to cease using the left hand and instructing the student to use the right. I am wondering why this is? Conformity? Personal bias? I hold my pens different than most people and they tried to break me of that habit but eventually gave up because the moment the instructor turned the back....I was at it again. I hold it between the first two fingers and use the thumb as against the fingers. I have occasionally found others who do that also.

Mercury said...


As I wrote, in days of old there may have been some advantages to have a preference, but it is just odd why the world favors right handedness now. If it is cultural, then "why"? But look on the bright side...from the predominate force that moves society--commerce. Someone has to make objects suited for the die-hard lefties.