The distinction between being left and right handed is one that causes confusion in society. According to Anything Left Handed, until the end of the 20th Century, some school teachers would hit children across the knuckles if they wrote with their left hand. Any difference within humanity seems to inevitably cause division, but as science investigates the differences between left- and right-handed people, the similarities begin to fall into view.
Many people believe that left-handed people are more intelligent than right-hand people -- Einstein, Benjamin Franklin, Leonardo da Vinci and Beethoven were all left-handed. This is backed up by a test conducted by Alan Searleman of St. Lawrence University in New York, which showed that there were more left-handed people with IQs of more than 140 than right-handed people. This might appear to make a convincing argument, but the evidence isn't conclusive and generally left-handed people are no more intelligent than right-handed people. Also, left-handed people are thought to process language through their right brain as opposed to their left brain, like right handers.
Physically, left-handed people are no different. If you were being pedantic, there is, of course, increased strength in the dominant hand, but being left handed does not bestow any other physical differences. In competitions, however, such as boxing, left-handers may have a marked advantage. Because most people are right handed, both left-handed and right-handed boxers are used to fighting right handers. This gives the left-handed boxer a distinct advantage, because he probably has a common, right-handed opponent, but the right handers have to fight someone "unusual." Although the results of such matchups appear to present evidence that left-handed people are physically superior, it is merely a matter of familiarity, and we can conclude that left-handed people's supposed superiority in one-on-one events is a result of the fact that left handers are a minority.
Even though scientists, such as Professor Clare Porac of Pennsylvania State University, report favouring a certain hand to be a result of differences in genes, right- and left-handed people still can share the same handedness gene. The genes responsible, according to Porac's article for Scientific American, are the "C" and "D" genes. The "D" gene stands for dexterous and leads to right-handedness. The "C" gene stands for chance, which means there is an equal chance of being left- or right-handed if you possess that gene. It seems that while many right-handed people will have a different gene to left-handers, some just as easily could have been lefties themselves. On the whole, it appears evident that while there might be fringe differences that correlate with differences in hand preference, there are more similarities between left and right-handed people than there are differences.