What are the possible reasons for dominance of right handedness in humans?

Answer 1

The right side of your body is controlled by the left side of your brain, and vice versa. Human beings tend to have a more developed left brain, at least in part in order to understand language. Since there are more neurons (in most people) on the left side, that side will generally have an easier time controlling its half of the body when a baby is developing. This creates a natural preferance that, over time, becomes hardwired. Left handed people tend to be more creative and artistic because they have a more developed right brain.

Interestingly, lefthanded and ambidextrous people have a higher incidence of both stuttering and dyslexia. Perhaps this relates to deficiencies in the left brain. But lefties fear not; you make more money and have more career success on average than righties.

Answer 2

Well... years ago people were forced to write with thier right hand so back then the percentage of people who were left handed was very small. More and more people now are becoming left handed because we no longer tell people they should fight it. Also, right handedness is the dominate trait in humans.

Answer 3

Forbidden_planet may be right about this trait being a spandrel, but caution is in order, as the spandrelist program is accused of much of that they accuse adaptionists of. Everything seems to be a spandrel to them. Gould and Lewotin are also grinding some Marxists ax's too. We do know that brain structure is quite variant between right and left handed people. So, as genes create the brain, it could very well be an adaption. Not enough is known to come to any hard a fast conclusion, though.

Answer 4

The reason is probably that certain things such as rock (or spear) throwing involve a huge amount of processing. This extra processing is to allow for redundancy for greater accuracy. There is a very interesting theory which demonstrates that much of the brain size of humans is actually for manually redundant tasks for greater dexterity and accuracy. Because it involves so much brain capacity, one side of the brain was favored to reduce brain strain. This led to our being right handed (most anyway). That way you can practice with one arm and you need less brain capacity than you would if you had to practice with both. Also one arm might be stronger and you don't need to feed the enlarged muscles of the other arm if you have one dominant for performing the task.

Answer 5

If your left hand is dominant, you'll hold a sword in that hand and a shield in the other. Against a right-handed person, you're at a much greater risk of getting stuck right through the heart.

Well, it's a possible reason. Much better answers appear above this one.

Answer 6

Left handers (like myself) have a recessive gene for left handedness. Right handedness is the dominant gene.
Thus more right handed people in the world...
thus more things designed for use of the right hand...
thus left handers die younger.

If you are looking for a evolutionary reason, good luck finding one.

Answer 7

Normalization and prejudice.
From a marketing viewpoint, it's simpler to convince left-handed people to use tools made for right-handed people than being creative enough to examine figures and open a new market about left-handed as can be done for other more outspoken minorities showing off that they have money to spend on their whims .
Prejudice comes from the fact that the left side still bears a negative stigmata from a cultural standpoint. It comes in handy in that prejudice never needs to be explained, but is caught immediately by most people. Prejudice is very inexpensive and cost-effective at that.

Answer 8

Probably a "spandrel." We should avoid the pitfalls of Panglossian functionalism in our discussions of evolution, and remember that there are also non-selectionist evolutionary mechanisms.

Answer 9

God's design of the brain