The “American Heritage Dictionary of the English Language” cites the conventional wisdom that the word “southpawIn boxing and some other sports, a southpaw stance is where the boxer has the right hand and the right foot forward, leading with right jabs, and following with a left cross right hook. It is the normal stance for a left-handed boxer.https://en.wikipedia.org › wiki › Southpaw_stance
Research shows left-handed people may have a lower risk of developing ulcers and arthritis. They may also recover more quickly from strokes. An older article in the American Journal of Psychology suggests that left-handed people may be better at divergent thinking, a thought process used to generate creative ideas.
So, with pitchers facing west when they stared into home plate, the arm of a left-handed hurler would be to the south side of the diamond. However, the earliest mentions of the term in baseball refer to position players, not pitchers.
Hand preference probably arises as part of the developmental process that differentiates the right and left sides of the body (called right-left asymmetry). More specifically, handedness appears to be related to differences between the right and left halves (hemispheres ) of the brain.
Left-handedness occurs in about 8% of the human population. It runs in families and an adoption study suggests a genetic rather than an environmental origin; however, monozygotic twins show substantial discordance.
Most of the current research suggests that left-handedness has an epigenetic marker—a combination of genetics, biology and the environment. Because the vast majority of the population is right-handed, many devices are designed for use by right-handed people, making their use by left-handed people more difficult.
“When we're left-handed, our right brains are usually dominant, and that's where creativity and intuition are centered. So it's often easier for us to be creative than logical.
In their analysis of 144 handedness and brain laterality studies—accounting for a total of nearly 1.8 million individuals—University of Oxford psychologists Marietta Papadatou-Pastou, PhD, and Maryanne Martin, PhD, found that males are about 2 percent more likely to be left-handed than females.
A 2011 study from the American College of Chest Physicians suggested that left handers have significantly higher chances of developing periodic limb movement disorder (PLMD). This disorder is characterized by involuntary, repetitive limb movements that happen while you sleep, resulting in disrupted sleep cycles.
In support of this, many studies have found that left-handed men are overrepresented among modern professional fighters, but studies typically find no difference in fighting success between left and right-handed fighters.
Lefties make up only about 10 percent of the population, but studies find that individuals who are left-handed score higher when it comes to creativity, imagination, daydreaming and intuition. They're also better at rhythm and visualization.
Queen Victoria is one of the most famous historical lefties. Although she wrote with her right hand, she painted with her left, which indicates she was made to switch as a child, as was sadly common in the Victorian era.
Clearly, being left-handed is not without its disadvantages.
However, left-handedness does not rise to the level of being a disability. The Social Security Administration has a list of all conditions which qualify as disabilities. This listing is commonly known as the “Blue Book”.
Left-handed and ambidextrous people are more susceptible to negative emotions, including anger. A small study published last year in the Journal of Nervous and Mental Disease found that the brains of lefties process emotions differently than those of righties, with more communication between the brain's two halves.
Lefties--or at least relatives of lefties--may be better than right-handed people at remembering events, according to a new study. Since the mid-1980s, scientists have known that the two brain hemispheres of left-handers are more strongly connected than those of right-handers.
But handedness has its roots in the brain—right-handed people have left-hemisphere-dominant brains and vice versa—and the lefties who claim Einstein weren't all that far off. While he was certainly right-handed, autopsies suggest his brain didn't reflect the typical left-side dominance in language and speech areas.
Special or not, lefties are born, not made: Genetics are at least partially responsible for handedness. Up until last year, it was assumed that hand preference comes from asymmetrical genes in the brain—two hands, two brain hemispheres, one is dominant.
Left-handedness is now accepted as a completely normal aspect of a child's development. A child's handedness will be fixed before they're born and won't be immediately apparent when they are an infant. Experts believe that if both parents are left-handed there is a 50-50 chance that a child will be left-handed too.
A study in The Journal of Nervous and Mental Disease suggested that those who are left-handed are more prone to negative emotions. It also found that when processing emotions, lefties have a greater imbalance in activity between the left and right brains.
Left-handedness and longevity
In addition, some diseases associated with left-handedness are relatively rare and there is no evidence that left-handedness is associated with increased risk of common diseases such as malignancy, cerebrovascular and cardiovascular diseases.
For example, if both parents are right-handed, there is a 1 in 10 chance of having a left-handed child. If the father is left-handed, the odds are 2 in 10. If the mother is left-handed, the odds rise to 3 in 10.
Our confidence intervals at a 95% confidence level show that the average IQ for a left handed person is between 117.73 and 127.19 and for a right handed person it is between 109.9 and 123.5.