11/23/83, Updated 5/5/01

What’s Right Is Right *

David A. Gershaw, Ph.D.

When we say, "What’s right is right," most people think that means, "What is correct is correct." Although that is one interpretation, it can also mean, "What is right handed is correct."

This is predominantly a right-handed world. In contrast, the left hand is not only seen as different or inconvenient — it is (or has been) seen as evil. If you look in the dictionary at the word, "sinister," the first definition is "threatening or portending (indicating) evil." It isn’t until you get several meanings down that you find sinister means "of or on the left side, left." This is one indication that sinistral (left-handed) people are seen as evil.

How many left handers are there? In monkeys there is an equal split (50%-50%) in handedness, right or left. In contrast, humans are predominantly right handed (90%-10%). In fact, there is evidence that humans have been predominantly right handed for at least 5000 years.

What determines handedness? There tends to be no real difference in the strength or dexterity of the hands themselves. The main reason for handedness lies in hereditary factors that determine which side of the brain will be more developed and therefore dominant. Typically the left side of the brain controls the left side of the head but the right side of the body — indicated by the shaded portions of the figure.

Likewise, the right side of the brain predominantly controls the right side of the head but the left side of the body (light portions of figure). This is because the nerves cross-over at the back of the neck.

Thus people with a dominant left side of the brain tend to be right handed, In fact, 97% of right handers are left-brain dominant. Contrary to what might be expected, 68% of left handers are also left-brain dominant. About 19% of lefties and 3% of righties are right-brain dominant. About 12% of lefties (close to 1% of the total population) show about equal dominance on both sides.

How can you tell if you are right-brain or left-brain dominant? The way you write is a good indicator. Most righties (who are left-brain dominant) write with their hand below the the line they are writing. Lefties with right-brain dominance write the same way. In contrast, the rare right handers who are right-brain dominant write with their hand hooked over the line they are writing. Similarly, lefties with left-brain dominance write with a hooked hand.

Beside being seen as potentially evil, there is an attitude that lefties are clumsy or awkward. They may have "two left feet," so they might get "left behind" or "left out." The right hand is seen as the skilled hand. In fact, the term for being right handed is "dextral." It has the same root as "dexterity," which refers to "skill in use of the hands." Being "ambidextrous" (equally skilled in both hands) infers that both (ambi-) hands are as skillful as the right hand should be.

Left handers live in a right-handed world.

Whatever clumsiness that occurs with lefties is most likely the result of living in a right-handed world. In a large scale study made of high school students in California, psychologists found no physical or mental defects associated with being a lefty. In addition, they found no differences in school achievement between righties and lefties.

In a few cases, left handedness is caused by birth traumas like premature birth, low birth weight and breech birth. In these cases, the lefties are more likely to have allergies, learning disorders and other problems. Otherwise, left handedness is not related to any difference in intelligence, accident rates or illnesses.

So being a righty is all right. However, there is nothing wrong with being a lefty. (I hope so; I am one!)

* Adapted from Dennis Coon’s Introduction to Psychology: Exploration and Application, Mayfield Publishing, 1983, pages 72-74. Updated from Dennis Coon’s Introduction to Psychology: Gateways to Mind and Behavior, Wadsworth Publishing, 2001, pages 74-77.

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