Abrams, which adeptly breaks down a mathematical explanation for why the rate of left-handed people has remained steady—about 10% of the population—for the last 500,000 years. The reason boils down to two words, “competition” and “cooperation,” and how the balance between those forces plays out in human societies.
Fetal development – some researchers believe that handedness has more of an environmental influence than genetic. They propose that environmental factors in the womb (including exposure to hormones) may influence whether we favour the right or left hand later in life.
While this is still contested, studies have found that artists like painters, musicians and even architects are mostly left-handers. Right and left-handed people deal with tasks and memory in different ways. Left-handers are known to efficiently multitask as they look at the tasks as a whole.
Several ideas have been proposed, including both environmental and genetics factors. For example, women might face stronger societal pressure to write with the right hand, but it could also be due to influences of hormones on brain development, or direct effects of specific genes on the X chromosome.
-Counting how many people are left-handed is more difficult than it looks, because of variations in preference and skill from task to task and because of left-handers having been forced to write with their right hand, but the best estimate we have is that roughly 10% of the world population is left-handed.
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.
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.
And it's also possible for two left-handed parents to have right-handed children. We don't fully understand what causes someone to be left or right handed. But we do know a wide variety of factors are involved, only some of which are genetic.
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.
'If a lefty writes with his right hand it's bad, because we're changing the hand but not the leading eye or the leading foot. ' So a child who has had his hand changed is more prone to distraction; he absorbs information more poorly. As a result, he can become more irritable.
“Most left-handers seem to have similar language processing to right-handers,” Grimshaw says. For other one-sided brain functions, such as attention, emotion, music, and face perception, she says, there are less data. “But for the most part, left-handers do not differ obviously from right-handers.
Overall, individuals with ADHD had a 27.3 percent chance of being either left-handed or mixed-handed compared to 18.1 percent in the general population. So the results suggest that the effects are smaller than for the autism spectrum, but generally go in the same direction.
Eleven percent of the population is born left-handed, and if they seem different, it's because they are! Learn six tips for raising a left-handed child.
In a study from 1975 on 7,688 children in US grades 1-6, left handers comprised 9.6% of the sample, with 10.5% of male children and 8.7% of female children being left-handed. Handedness is often defined by one's writing hand, as it is fairly common for people to prefer to do a particular task with a particular hand.
The researchers found that people in the Netherlands are the most likely to report being left-handed, at 12.95 per cent, followed by the United Arab Emirates, Israel and Puerto Rico. China, however, has the lowest reported rate at 2.64 per cent, followed by Indonesia, Vietnam and Hong Kong.
Sometimes people who are left-handed are called many different things, “Southpaws”, "Lefties", and other simply mean names, like "Weird" or "Strange".
Current theories suggest that the environment plays a significant role here. Handedness is most likely due to a combination of both genes and environment while some people have a greater chance of being left-handed if their parents are.
Generally, left-handedness is found in 10.6% of the overall population. Some studies have reported that left-handedness is more common in twins than in singletons, occurring in 21% of people who are twins.
From being better at problem-solving to having extra talents in the arts, the paper claimed that left-handed folk could be more gifted all round. It's a theory that makes sense considering some of the most brilliant minds in history were left-handed, from Marie Curie and Leonardo da Vinci to Sir Isaac Newton.
A study of “handedness” by the National Bureau of Economic Research reveals the earnings power of highly educated left-handed men was 15 percent greater than that of their right handed peers. Leftie women showed no increase in their earnings.
Sometimes children who are left-handed can find handwriting difficult. Having to push the pen across the page towards their body can be awkward for them. Changing their body, paper or hand position for writing, their pen hold or changing the equipment they use can all help them achieve a fast, fluent writing style.