Human Research of Humans
—   Left brain vs Right brain
—   Left handed vs Right handed
Below you'll find a few snippets from research on the human brain — Left handed vs Right handed, etc.   In fact, it was similar (often silly) studies that supported my parents much ill-founded reluctance to let me near anything with two wheels and a motor.  Of course it was okay for them to ride motorcycles when they were young, but to let me on a murdercycle — no way.
Just one of those dichotomies my parents used to serve me.
Geneticist Richard Epstein says that a "novelty-seeking" gene may be associated with adventurous behavior.  Babies in his study who possess the gene will more easily follow visual and auditory stimulation, and, Ebstein theorizes, "A child who, even at two weeks reacts strongly to visual and sound stimuli, seems to be alert, doesn't get scared, doesn't freeze in the crib — that same person as a grownup is willing to go mountain climbing and drive too fast."
Adding to this, some of my favorite racers are left handed; Ayrton Senna, Kimi Räikkönen, Valentino Rossi, Troy Bailiss, Carl Fogarty, Ben Spies, Carlos Checa, Eugene Laverty, etc.
Judging from my supposedly irrational behaviour (both in school and at home), at age 7 they decided to run some tests on me.  The studies concluded that, along with being very left-handed, my brain was predominately right-sided.  To straighten this up, they tried to force me to write with my right hand.  But of course, even that failed — I wasn't the kind of a kid who would easily comply to such an imposition.  Below you'll find a definition of this "Left brain vs Right brain" theory.
One theory of the structure and functions of the mind suggests that two different sides of the brain control two different ways of thinking.  It also suggests that each of us prefers one way over the other.  Research has shown that the two different sides, or hemispheres, of the brain are responsible for different manners of thinking.  The following illustrates the general differences between left-brain and right-brain thinking:
Looks at parts
Looks at wholes
As if that wasn't enough, back in 1985, Canadian researcher Sandra F. Witelson concluded in her "The Brain Connection: The Corpus Callosum is Larger in Left-Handers" — here, freely stipulated & quoted:
Left-handed advantages may lie in certain intellectual capacities (among other things).  For instance, there's some hints of broader and deeper connections between the two brain hemispheres of left-handers compared to right-handers.  The corpus callosum of left-handers is some 11 percent greater in size than that of right-handers, indicating greater integration of both brain hemispheres in processing information.
Another intellectual advantage of left-handers could be greater resistance to suggestion or persuasion; of course, this may also point to greater aggressiveness on the part of left-handers in general, and could just as easily be a disadvantage in many situations as a boon.  For instance, it might lead lefties to question everything they are shown or told, which could slow them down in traditional education and training environments.  But in cases of brainwashing, harmful peer pressures, con games, and cult indoctrination it would seem an extra defensive edge for the lefties.  They may not so easily be talked into things as their right-handed brethren.  One clue to all this is the greater difficulty in hypnotizing the left-handed relative to the right-handed.  Righties concentrate more easily and intently than lefties.
Research also shows that in sports; the smaller the distance between the participants the more the overrepresentation of left-handedness it gets:  For example, close interactive sports such as tennis, badminton, martial arts, etc., have an overrepresentation of left-handedness, while non-interactive sports, like swimming, running, etc., have not.  Hence, the closer the physical distance it gets, the more skewed towards left-handedness it becomes — e.g. in fencing, about half of the participants are left-handed, and boxers & martial arts fighters (a study of almost 10,000 people) lefties were far more overrepresented and also at a higher percentage of winning their fights.
However, and unfortunately, other differences between left and right-handed include: In the future world of the 20th century, left-handers will be much more susceptible to serious accidents throughout their lives than right-handers.  Soon about only one percent of surviving 80-year olds will be left-handed — lefties hold their own mortality-wise with righties until around age 33, after which the tide turns decidedly against them.  Left-handers will also seem more prone to immune system and neurological problems, as well as smoking, alcoholism, and certain types of cancer, thus lowering their overall life expectancy compared to right-handers.
Sure, it's quite inaccurate and certainly unfair to paint with such a broad brush, but I must admit that stuff like this is kind of interesting.  Also is the fact that throughout history there have been in proportion more scientists, artists and musicians, who were left-handed.  However, it should also be mentioned that there have been, proportionally, more "eccentric" left-handed leaders than right-handed ones — Napoleon Bonaparte, Adolf Hitler, Joseph Stalin, Winston Churchill, Margaret Thatcher, Fidel Castro, Che Guevara, Harry Truman, John F. Kennedy, Alexander the Great, Julius Caesar, Joan of Arc, Mahatma Gandhi, Saddam Hussein, Osama bin Laden, Benjamin Franklin, Bill Clinton, Al Gore, Barack Obama, John McCain, George Bush (41), Ronald Reagan, Gerald Ford, Colin Powell, Norman Schwarzkopf, George Patton, Jack the Ripper... to name a few.   (Well, Jack the Ripper wasn't really a leader ... but I guess you get the point.)