reprinted from CBC Canada

They’ve been vilified throughout history as gauche, sinister and wrong-headed. So what is the truth about lefties? It turns out there is little consensus among scientists about what causes handedness or what it means to be a southpaw. Some researchers believe the trait comes down to genetics. Others propose that environmental factors or brain trauma at birth might be at the root of the behaviour. We spoke to some of the few scientists digging into the causes and effects of being a lefty in a right-handed world:

Dr. Pamela Bryden is a professor of kinesiology at Wilfrid Laurier University in Waterloo. She's found that lefties were definitely more flexible and adaptable when she measured their abilities to perform tasks with their non-dominant hand.

Dr. Amar Klar is a geneticist at the National Cancer Institute in Maryland. Dr. Klar decided to study left-handedness by heading to a shopping mall to study the hair whorls on the tops of shoppers' heads. That study led him to believe that most people inherit a single dominant gene for right-handedness, but without that gene, a person has a 50 per cent chance of being a left-hander.

Dr. Chris McManus is a professor of psychology at University College London and author of Right Hand, Left Hand: The Origins of Asymetry in Brains, Bodies, Atoms and Cultures. He believes there is a gene for right-handedness. But he thinks an evolutionary quirk occurred tens of thousands of years ago that caused a gene mutation, which Dr. McManus calls the "chance gene". It cancels the bias to the right, so those who inherit it have a 50-50-chance of ending up lefties.

Dr. Ira Perelle is a professor in the department of psychology at Mercy College in New York. He believes there are at least three possible causes for left-handedness, including the possibility that at a very young age, a child can learn the behaviour.

It is amazing what people will do if they have a little spare time. Take me for example I like to make waffles and eat them wearing lederhosen ... uhhh .. nevermind).

Justin and Drew are cartoonists that thought it would be fun to draw some cartoons with their left-hands.

My personal favorite

reprinted from the American Scientist

Handedness is closely tied to the way hair spins on the scalp
Christopher R. Brodie

Is handedness genetic? The question is centuries old and has been the subject of hundreds of scientific papers. Now, the verdict is finally in, and the answer is yes. But there is an unexpected twist to the story: It seems that the same gene that creates lefties also determines which way hair whorls around.

Amar Klar, the head of developmental genetics at the National Cancer Institute campus in Frederick, Maryland, explained the link between handedness and the way hair spins on the scalp in the September 2003 issue of Genetics. It seems a single gene with two alleles controls both traits. The dominant allele dictates right-handedness—and a clockwise hair spiral.

Continue reading "Head in Hand" »

reprinted from the Purdue News

August 5, 2003

WEST LAFAYETTE, Ind. – It may be a right-handed world, but recent Purdue University research indicates that the first building blocks of life were lefties – and suggests why, on a molecular level, all living things remain southpaws to this day.

In findings that may shed light on the earliest days of evolutionary history, R. Graham Cooks and a team of Purdue chemists have reported experiments that suggest why all 20 of the amino acids that comprise living things exhibit "left-handed chirality," which refers to the direction these basic biological molecules twist–and how a single amino acid might be the reason.

Continue reading "Purdue scientists discover why we’re all lefties deep down" »

Interviewer - Now Chris, you wrote a book, 'Right Hand, Left Hand', which won you a whole heap of prizes because it's something people are absolutely fascinated by. Why do these left-handers exist?

Chris M - The simple answer is because of genes. Some of us have one set of genes while others of us have another. It's the same reason that some people have blue eyes or blond hair. And therefore, some people just have their brains the other way round. That's the simple answer. The really difficult question to answer is why did that ever happen? Why did we become mostly right handed in the first place and why did others become left handed? That's a good evolutionary story as there have to be advantages to being right handed and advantages to being left handed. They're difficult questions.

Continue reading "The Naked Scientists Interview with Author of Right Hand-Left Hand" »

reprinted from the New Scientist

NewScientist.com news service
Will Knight

Left-handed people may be better equipped for close range mortal combat than those who rely on their right hands, according to researchers.

Charlotte Faurie and Michel Raymond of the University of Montpellier in France examined the number of left-handed people in unindustrialised cultures as well as the homicide levels within each culture.

Continue reading "Left-handers win in hand-to-hand combat" »

reprinted from the Pew Research Center

by Richard Morin
August 9, 2006

Left-handed men who attended at least a year in college go on to earn significantly more than their right-handed classmates -- one more reason they'll be celebrating International Left-Handers Day this Sunday.

"Among the college-educated men in our sample, those who report being left-handed earn 13 percent more than those who report being right-handed," report economists Christopher S. Ruebeck of Lafayette College and his research partners Joseph E. Harrington, Jr. and Robert Moffitt of Johns Hopkins University in a new working paper published by the National Bureau of Economic Research.

And lefties, stay in school: Those who finished all four years of college earned, on average, a whopping 21 percent more than similarly educated right-handed men. Curiously, the researchers found no wage differential between left- and right-handed women.

They also found that lefties were more likely to be found in certain kinds of jobs. "For example, 53 percent of those who are left-handed are in professional occupations, compared to 38 percent of those who are right-handed," they reported.

They based their conclusions on an analysis of data from the federally-funded National Longitudinal Survey of Youth, a nationally representative survey of approximately 5,000 men and women first interviewed in 1993 when they ranged in age from 14 to 21 years old. Their analysis was based on a 1993 follow-up survey, when respondents were ages 28 to 35. Left-handers comprised about 10 percent of their sample, just as they comprise about 10% of the population as a whole.

While evidence of a wage gap was unequivocal, explanations for the disparity were more elusive. The authors suggested that greater innate ability, perhaps due to differences in biology and brain function are two possibilities. But they do not know why they didn't see a similar effect among women.

"Gender discrimination may be obscuring the effects for higher-educated left-handed females," Ruebeck wrote in an e-mail. "The biological literature also suggests differences in cognitive style across handedness in males that do not exist in females. If these differences are responsible for left-handers' higher wages, then we would not expect to find the same result in females."

The study is the latest to suggest there's something special about lefties. Other researchers have found that left-handers are over-represented in some disciplines on university faculties, as well as among gifted students, artists and musicians. And as any pro baseball player will tell you, there are entirely too many southpaws pitching in the big leagues.

The Left Handers Club was founded in 1990 by Lauren Milsom and 2 years later she/they promoted the first Left Handers Day on August 13

In addition they claim to have

Angelique Chrisafis, Arts correspondent
Guardian

Thursday June 6, 2002

Over the centuries they have been beaten on the knuckles, locked up, ridiculed and prevented from reproducing in case they spawned freaks.

Now left-handers are facing another affront. A psychology professor told the Guardian Hay festival yesterday that society will never stop being biologically and culturally dominated by right-handers at the psychological expense of those who hold their pencil in their left hand.

Continue reading "Why left-handers still feel left out" »