Although the percentage varies worldwide, in Western countries, 85 to 90 percent of people are right-handed and 10 to 15 percent of people are left-handed. Mixed-handedness (preferring different hands for different tasks) and ambidextrousness (the ability to perform tasks equally well with either hand) are uncommon.
Most humans (say 70 percent to 95 percent) are right-handed, a minority (say 5 percent to 30 percent) are left-handed, and an indeterminate number of people are probably best described as ambidextrous.
About 90 percent of people are right-handed, says Corballis. The remaining 10 percent are either left-handed or some degree of ambidextrous, though people with "true" ambidexterity—i.e., no dominant hand at all—only make up about 1 percent of the population.
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.
Studies suggest that approximately 10% of people are left-handed. Ambidexterity refers to having equal ability in both hands. Those who learn it still tend to favor their originally dominant hand. This is uncommon, with about a 1% prevalence.
Billionaire Bill Gates and Facebook founder Mark Zuckerburg are left-handers.
In fact, the difference is 90:10. This means that dyslexia may be more commonly found in left-handed people but the relationship is not necessarily causal. There is also the question of whether or not it is more common in boys than girls.
If two parents are right-handed, their offspring has a 10% chance of being left-handed. However, if one or both parents are left-handed, the chance of their child being left-handed becomes higher at 18 to 22% and 27%, respectively.
This is most likely because the left and right hemispheres control motor action on the opposite sides of the body. While this relationship is not straightforward, it would appear that, in most cases, handedness and brain lateralisation go hand in hand (pun intended).
Mixed dominance or cross laterality happens when a person doesn't favor the same side of the body for a dominant hand, foot, eye and ear. Some parents notice that their children with developmental delays may not have a dominant hand when completing all activities.
'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.
Yes, Albert Einstein was ambidextrous, which means he was able to use both his left and right hands equally well. Einstein was known to use his left hand for writing, but he was also able to use his right hand for tasks such as drawing and playing the violin.
Most children have a preference for using one hand or the other by the age of about 18 months, and are definitely right or left-handed by about the age of three. However, a recent UK study of unborn babies found that handedness might develop in utero.
For example, it is often cited that around 95% of right-handers are “left hemisphere dominant”. This is not the same as the “left brain” claim above, it actually refers to the early finding that most right-handers depend more on the left hemisphere for speech and language.
However, when both were combined it was shown that people with ADHD had a statistically significant increase in left-handedness and mixed-handedness combined compared to the general population.
In a review of 12 studies including a total of 497 individuals diagnosed with ASD, Rysstad and Pedersen (2016) found 16% left-handers and 44% mixed-handers, giving a total of 60% non-right-handers.
The results show evidence of a trend towards elevated levels of atypical handedness when it comes to differences in left- and mixed-handedness (p = 0.09 and p = 0.07, respectively), but do show clear evidence of elevated levels of non-right-handedness between individuals with ADHD and controls (p = 0.02).
The principle identification of Jack the Ripper as a lefty comes from Dr. Rees Ralph Llewellyn.
Queen Victoria is perhaps the most famous left-handed British monarch, though historians believe she was required to use her right hand as a child during the strict age in which she lived.
Left-handers, rejoice! Marshall Bruce Mathers III (A.K.A. Eminem) is an esteemed member of your crew.
McManus which found that the Netherlands has one of the world's highest prevalences of left-handedness at 13.23 percent. The United States isn't far behind with a rate of 13.1 percent while neighboring Canada has 12.8 percent. Elsewhere, rates of left-handedness are far lower and China is a good example.
And, there does seem to be a larger percentage of lefties among the highly intelligent. (The web is full of references to high IQ society claiming that 20 percent of its members are left-handed, but a call to the high IQ society revealed they do not track such data.)
One biological effect on hand preference is known to be sex, with males more likely to be left-handed than females2,14. For example, in a U.S. dataset aged 10–86 years, the proportion of non-right-handers among 664,114 women was 9.9%, versus 12.6% among 513,393 men2.