Why are some people left handed?

Answer 1

to be right handed is a dominant trait, the left is recessive, plus with the the left hand you put your hand in a more awkward postion. :) get it? hope you do if you dont know what dominant and recessive traits are, it has to do with genetics.

Answer 2

if you are left handed then you were born that way

There is a gene for right-handedness, but not for left-handedness. If you have the gene, you are an obligate right-hander, barring something like being born without a right hand, or an injury near birth to the part of your brain that controls your right hand.

If you don't have the gene, then you have a 1 out of 2 chance of being left-handed, or, that is to say, equal chances of having either hand dominant.

No one is sure why people without the gene become right- or left-handed, but handedness seems to appear very early, and there seems to be an advantage to it. In species like domestic cats, where some appear to have a dominant paw (more often the left), and others do not, the ones with a dominance, no matter which side, learn new tasks more quickly. Autistic children often are very slow to establish a hand preference. At any rate, events in utero are likely to at least influence handedness, but may be as quirky as a fetus in a position where it can move one arm and hand more freely than the other; or one that has a little better blood flow to either one arm, or one side of the brain, may develop dominance that way-- which is not the same as having an injury-- nothing will be wrong with the other side; it just isn't dominant.

Left-handed people usually perform right-handed tasks better than right-handed people perform left-handed tasks, and it once was thought that this was because they lived in a right-handed world, but since the gene was discovered, and the chance right-handers can be sorted out, it seems that they perform much better at left-handed tasks than genetic right-handers. Non-genetic righties sometimes will have a few tasks that they naturally do left-handed, usually tasks that involve hand-eye coordination, and favor the eye with better vision, like firing a rifle, or hitting a Baseball (and the same is of course true for left-handers).

Left-handers are slightly over-represented among people with learning disabilities, and many of those who do have an overhand style of writing, rather than writing in a way that mirrors right-handed writing. There is a theory that the overhand writers with learning disabilities may represent genetic right-handers who use their left hands due either to some minor birth trauma, or slight miswiring in their brains. Their disabilities are usually minor, and this is just a theory, though.

A statistical quick that seems counter-intuitive, but is explained by the existence of the right-hand gene, is that identical twins are more likely to come in a right/left pair, than two lefties. The reason for this is that about 80% of the population has the right-handed gene, and 20% does not. So, 80% are obligate right-handers, 10% are chance right-handers, and 10% are chance left-handers (the numbers are rounded and approximate). The same percentages are true for identical twins. If we think of twins in AB pairs, and just look at the 20% without the gene, we see that 25% will be a R/R pair, 25% will be a R/L pair, 25% will be a L/R pair, and 25% will be a L/L pair. Each 25% is 5% of the total population. The 25% of R/R pairs join the obligate right-handers, and seem no different. So we are left with the L/R pairs and the R/L pairs. Statistically, they are different groups, but practically, they are not, so really, 50% of the subgroup, or 10% or the total, are pairs with one rightie, and one leftie. That leaves just 5% of the population who are L/L pairs.

Answer 3

Most products are designed for the majority. Being that right-handedness is more common, left-handed people spend more time using products that they are not accustomed to as right-handed people.

The truth is, they're not. My grandson is left-handed and he's worse with his off-hand then I am with mine and I'm right-handed. As far as I'm concerned, the most ambidextrous people have been right handed. In sports, lefties are usually considered single-sided. Righties are far more well rounded than lefties and is why you see far fewer left-handed point guards in Basketball than righties. Perhaps, it's because a lot of us right-handers who are into sports, are fascinated with being able to use our left hands. I used to practice for hours throwing with my left arm, left-handed layups and dribbling with my left hand just to say that I could do it.

Answer 4

Handedness is believed to be determined by a combination of genetic and environmental factors. Around 10% of people are naturally left-handed due to differences in brain structure and development. There is still ongoing research to fully understand the reasons behind left-handedness.

Answer 5

because the right hand gene is dominant over the left , usually the only way somone is left handed is if both parents were

Answer 6

• They are left handed because God made them that way.

Answer 7

Beacuse they are smarter than you.and they are also left hand for you to ask why are they :)