Meaning, Causes, and Possible Health Effects
The term “handedness” refers to the tendency to use one hand over the other, such as left-handedness or right-handedness. It’s also known as hand preference.
So, if you naturally use your right hand to perform tasks, you’re right-handed. If you naturally use your left hand, you’re left-handed. But if you can use both hands to perform tasks, you’re considered to be ambidextrous.
Ambidextrousness, or ambidexterity, is sometimes called mixed-handedness, though the terms are slightly different. Ambidexterity is the ability to use either hand to skillfully perform tasks. Mixed-handedness is the tendency to use different hands for different tasks. It usually refers to preference, not skill.
There’s less research on ambidexterity than on mixed-handedness. However, since both involve using both hands, research on mixed-handedness might shed some light on ambidexterity as well.
Read on to learn about the possible causes and risks associated with being ambidextrous.
The exact cause of ambidexterity is unknown, but there are several theories.
Cultural preference for right-handedness
It’s thought that many people with ambidexterity are actually left-handers who have taught themselves how to use their right hand.
This is due to the cultural preference for right-handedness.
Historically, many objects have been designed for right-handed people. Some examples include:
- can openers
- scissors
- the number pad on keyboards
- classroom chair desks
So, one theory is that ambidexterity comes about when left-handed people use right-handed objects.
In fact, many people who identify as ambidextrous tend to write with their right hand. This may emphasize how society prefers right-handedness.
Pain in the left hand
Another possible explanation relates to injuries or pain.
If a left-handed person injures their dominant hand, they might be forced to perform tasks with the other one. As a result, they can become ambidextrous. The same can be true for a right-handed person who injures their dominant hand and learns to use their left.
Genetics
It’s possible that genetics might play a role. A 2021 study found seven gene variants associated with ambidexterity. However, more research is needed to understand these variants.
Imbalanced coordination between brain hemispheres
The brain consists of left and right hemispheres. These hemispheres work together to perform various functions, like remembering information.
Ambidexterity might be due to an imbalance in this coordination. But again, more studies are needed.
True ambidexterity is rare. Approximately 1 percent of the population is ambidextrous.
Ambidexterity is also more common in males than females, the 2021 study mentioned earlier suggests.
People use the terms “ambidextral” and “ambisinistral” to describe different levels of ambidextrousness.
Ambidextral refers to ambidextrous people who use both hands like a right-handed person’s right hand. Likewise, ambisinistral refers to ambidextrous people who use both hands like a left-handed person’s left hand.
These terms aren’t widely used in science, though. More research is needed to determine if there actually are different types of ambidextrousness and how they differ from each other.
Again, the research on ambidexterity is lacking. No studies explicitly examine the link between ambidextrousness and health risks.
However, researchers have examined risks related to mixed-handedness, which involves using different hands for certain tasks. There’s also research on left-handedness and risks, which may apply to ambidextrous people who are actually left-handed.
Here’s what the science says so far:
Attention deficit hyperactivity disorder (ADHD)
Cerebral laterality refers to the fact that one side of the brain specializes in certain functions, while the other side specializes in others. It’s also known as lateralization of brain function.
According to a 2010 study, mixed-handedness is associated with atypical cerebral laterality. It’s also linked to ADHD in children and adolescents.
Researchers in a 2015 study also note that non-right handedness is associated with ADHD symptoms. Non-righthandedness includes ambidextrous people, which may include those who were originally left-handed.
Schizophrenia
There’s some speculation that ambidextrous or mixed-handedness people have a higher risk of developing schizophrenia.
According to a 2021 study, ambidexterity is associated with variants in the gene VRK2. This gene is also involved in the development of schizophrenia as well as major depressive disorder, according to a 2018 study.
Additionally, a 2013 study found a connection between left-handedness and schizophrenia. This association may also apply to ambidextrous people who are actually left-handed.
Post-traumatic stress disorder (PTSD)
A 2007 study found that veterans who use both hands in combat are more likely to develop PTSD. This is a mental health condition that occurs after experiencing a scary or shocking event.
According to the study, atypical cerebral lateralization may be related to PSTD. It’s thought to increase a person’s sensitivity to threats, potentially increasing the risk for PTSD.
As mentioned earlier, abnormal cerebral lateralization is associated with using both hands. This might explain the link between PTSD and ambidexterity or mixed-handedness, though more research is needed.
Learning difficulties
Atypical lateralization of the brain, which is involved in ambidexterity and mixed-handedness, may also cause learning difficulties in children.
According to a 2015 study, this may be related to trouble with skills like:
- verbal fluency
- writing pace
- retrieving information
The study also notes that children with an inconsistent hand tendency are less coordinated than those who are just right- or left-handed. This may affect learning in school.
Synesthesia is a neurological condition in which one sense, like hearing, is perceived by another sense, like sight. For example, a person with synesthesia might see colors when they hear sounds.
Currently, there’s no research that directly links ambidexterity with synesthesia. But it’s said that left-handed people are more likely to have synesthesia. So, an ambidextrous person who is actually left-handed might be more likely to have the condition.
Ambidextrousness is the ability to skillfully use both hands. It’s similar to mixed-handedness, which involves using different hands for different tasks.
Researchers are still learning about ambidexterity. The exact cause is unknown, but it’s thought that many ambidextrous people are left-handed individuals who have learned how to use their right hand. Certain genetic variants might also play a role.
Being ambidextrous may be associated with ADHD, schizophrenia, and PTSD. More studies are necessary to understand the causes and risks of ambidexterity.
Things You Didn’t Know About Ambidextrous People
A tiny fraction of the population can use both hands with equal skill.
Here’s the biology behind this cool ability, plus some other tidbits you never knew.
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There are very, very few of them
Truly ambidextrous people only make up about 1 percent of the population. People who have no dominant hand, and can use both hands with equal skill, are about 1 in 100, though many people who are left-handed can use their non-dominant hand nearly as well as their dominant one.
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There are a couple of variations
The rarest form of ambidexterity is when people can use both hands with strong skill, all the time. These people can be called “ambidextral,” which means “pertaining equally to the right-hand side and the left-hand side.” There are other people, however, who don’t have equal skill with both hands but who use their right hands for some things and their left hands for others. Another term altogether, “ambisinistral,” refers to people who have no dominant hand, and use both hands… but neither hand is very strong. As Mental Floss puts it, both hands have the approximate skill of a right-hander’s left hand. Here are 14 hilarious tweets all lefties will relate to.
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It’s all in your head
Ambidexterity indicates that the left and right sides of that person’s brain are pretty much symmetrical (which is true for lefties, too!) On the other hand, right-handed people tend to be left-brain dominant. Here’s more about how your brain determines which hand you prefer.
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Many of them started out as lefties
Since ambidextrous and leftie brains are so similar, it’s only natural for one to start out as the other. For hundreds of years, there was quite a stigma surrounding left-handedness, as the left hand carried Biblical associations with witchcraft and demons. The word “sinister” comes from the Latin word “sinistra,” which originally meant “left.” Many left-handed people, from the Middle Ages to the 21st century, experienced pressure to use their right hands instead and ended up developing ambidexterity. Other people, meanwhile, may become ambidextrous after injuring their dominant hand.
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Academia may not be their strong suit
Surprisingly, even though this skill is so connected to the brain, ambidextrous people tend to be more in tune with their physical abilities than their mental ones. It may be for this reason that they tend to perform more poorly on general intelligence tests than people who favor one hand. In a Finnish study, seven- and eight-year-old children completed several different academic tests. 87 out of the 8000 participants were comfortable using both hands. The ambidextrous students were 90 percent more likely than the right-handed ones to struggle with math problems and were also more likely to have difficulties with language.
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It also has ties to ADHD…
In the same Finnish study, left-handed and ambidextrous teenagers were twice as likely as right-handers to show signs of ADHD. Of the teenagers in the study who’d already been diagnosed with ADHD, the ambidextrous ones showed more severe symptoms.
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…and schizophrenia
The gene that contributes strongly to left-handedness, LRRTM1, also increases a person’s risk for schizophrenia. Since left-handed and ambidextrous people’s brains are so similar, ambidextrous people are at a higher risk for the condition as well. On the flip side, schizophrenics are far more likely to be left-handed or ambidextrous than the rest of the population. Here are other hidden dangers that come with being left-handed.
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They’ve got skills and their share of famous representatives
Ambidexterity tends to give people a major advantage in activities such as music, art, and sports. Leonardo da Vinci, Ben Franklin, and Albert Einstein are some of history’s most famous ambis. (Franklin signed the Declaration of Independence with his left hand!) Maroon 5 frontrunner Adam Levine, while not totally ambidextrous, writes with his left hand but does most other things with his right. Figure skater Michelle Kwan and LeBron James are just two of the many athletes skilled at using both hands.
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Their emotions are more adaptable
According to a Montclair State University study, ambidextrous people are more likely to experience a change in their emotions based on their surroundings. The authors of the study tried to trigger certain emotions in the participants. Right-handed people tended to be more resistant to the rapid emotional change than the left- and multi-handed participants.
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Ambidexterity often comes hand-in-hand with synesthesia
The brains of ambidextrous people tend to be pretty symmetrical—a trait they share with people who have synesthesia. If you’ve ever heard about people being able to hear colors, feel physical sensations that other people are feeling, or even associate numbers with personalities, all of those sensations are variations of synesthesia. This fascinating brain condition triggers more than one of the five senses at once. A person with synesthesia is far more likely to be left-handed or ambidextrous than the average person is. Now that you’ve learned about all the amazing things about ambidextrous, check out the 25 famous left-handed people you probably never knew before.
[Sources: Mental Floss, mindamuse.com, National Geographic, wisegeek.com]
Originally Published: March 19, 2019
Meghan Jones
Meghan Jones is a word nerd who has been writing for RD.com since 2017. You can find her byline on pieces about grammar, fun facts, the meanings of various head-scratching words and phrases, and more. Meghan graduated from Marist College with a Bachelor of Arts in English in 2017; her creative nonfiction piece “Anticipation” was published in the Spring 2017 issue of Angles literary magazine.
Why ambidexters are good with both hands and is it worth learning
September 15, 2020
Life
Lifehacker understands the causes of a rare phenomenon, which many consider a sign of genius.
In almost 90% of people, the right hand is dominant, in the rest – the left. And only about 1% of the population are ambidexters. They perform all tasks equally well with both hands.
There are also people who change hands for different tasks. For example, they write with the right, but the ball is thrown with the left. This is called mixed arm dominance. It often occurs when playing musical instruments. For example, guitarists, pianists, and drummers successfully use both hands while playing. Only each of them is trained for different actions.
These people are not ambidexters. They will still find it difficult to write or eat with their non-dominant hand. Ambidextrous, on the other hand, do not have such difficulties: it is equally easy for them to hammer a nail, brush their teeth or hit a tennis ball with both their right and left hands.
What explains ambidexterity
So far, scientists know little about the causes of ambidexterity and, in general, why this or that hand becomes the leading one. But research has found a link between hand preference and cerebral asymmetries.
The left and right hemispheres are associated with different mental functions. This division of tasks helps the brain save energy and process information faster. It cannot be said that the left hemisphere is responsible for logic, and the right for creativity: this is too rough a simplification. However, the hemispheres are not symmetrical in structure and function.
During the development of the organism, speech centers are formed in one of the hemispheres. Most often – in the left. And it is also responsible for the work of the right limbs.
Therefore, there is a theory that explains the number of right-handers in terms of evolution. According to her, the left hemisphere has become the leading one because of the importance of the language skills for which it is “responsible”. It also controls the right hand, which is why most people have become right-handed. Among other primates, right hand dominance is not as common. Some individuals prefer to use it, but this does not cover the entire population.
However, this theory is not complete. Many animals, including mice, frogs, and fish, have a preference for one side, although they cannot talk.
Ambidextrous brains are more symmetrical. And if the hands perform tasks with the same quality, then both hemispheres are associated with the same functions. So far, scientists have not agreed on whether this is an advantage or a disadvantage.
Is it worth developing ambidexterity
It is not known exactly how learning this skill affects the brain. Although various trainings promise that using the non-dominant hand strengthens connections between neurons and increases creativity, there is no evidence for this.
Some scientists even believe that congenital ambidexterity is associated with problems in speech and reading, as well as attention deficit. It is assumed that this is caused by rivalry between the cerebral hemispheres. The asymmetry has evolved in order for each hemisphere to specialize in separate functions.
In the symmetrical brain of ambidexters, the hemispheres receive the same sensory information. And this, perhaps, slows down the thinking processes.
However, so far all these are only hypotheses. There is no evidence that working with the non-dominant hand will lead to psychological problems. Therefore, it is up to you to decide.
How to train your non-dominant hand
- Write or draw with both hands at the same time. To prevent a piece of paper from moving around the table, secure it with something. At first, the words and drawings will be very crooked, but after a couple of weeks it will get better. The main thing is to train every day at least a little.
- Write with your non-dominant hand. For example, learn how to print the alphabet in uppercase, lowercase, and italics. Pick up a pen that glides easily over paper and practice daily.
- To make writing easier, don’t squeeze the pen too hard or your hand will hurt. If you are right-handed, rotate the piece of paper 30 degrees clockwise. If left-handed – 30 degrees against.
- Write with your dominant hand while looking in the mirror. You will see what your non-dominant hand will look like as you write. So it will be clearer how to arrange it, and the picture will be deposited in the brain.
- Strengthen the muscles in your non-dominant arm. Lift dumbbells or just something heavy, gradually increasing the weight.
- Try cooking with your non-dominant hand. Do not take the knife: it can be dangerous. First, beat the eggs and mix the ingredients in a bowl.
- Do simple everyday things with her: brush your teeth, hold a spoon, bounce a ball off the floor and walls.
- Gradually move on to difficult, non-hazardous tasks. Perform them only with your non-dominant hand to strengthen the skill. However, keep in mind that if you start using both hands too early, the dominant will still have an advantage, because you have used it all your life.
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Is it possible to strengthen the brain by becoming ambidextrous? / Habr
Can the acquired skill of writing with both hands make your mind sharper and faster? Can training students to use their non-dominant hand improve their performance on exams? Such claims have been made for more than a hundred years.
Right-handedness or left-handedness is one of the deepest mysteries of neurology. We still know very little about what it means for the brain to be left-handed or right-handed, or what effect learned ambidexterity will have on the brain.
By the age of four, we develop a preference for using one hand over the other, which remains with us for the rest of our lives. Most of us prefer the right hand, and most of the rest prefer the left. But a tiny fraction, less than one percent, live ambidexters. This property is innate and partly controlled by genetics. It is also seen in other animals, including primates. But the reason for the predominance of right-handedness is still not clear.
We know that hand choice is associated with an asymmetry in how the brain works: the left hemisphere controls the right side of the body, and vice versa. For the majority, it also contains speech centers, and therefore it is often argued that it prevails over the right.
Historically, lefties were stigmatized, punished, and forced to relearn, but in the late 19th century, a movement emerged touting the benefits of ambidexterity. In 1903, John Jackson, Senior Lecturer at the Grammar School in Belfast, founded the Ambidextral Culture Society. Jackson and his followers believed that the hemispheres of the brain were distinct and worked independently, and that the predominance of right-handedness wasted half the educational potential.
Jackson wrote that with ambidexterity training “each hand will be independent of the other in the production of any work… if necessary, one hand will be able to write a letter and the other to play the piano, without loss of concentration or ability.” And the universal use of ambidexterity, as a result, was to lead to a brave new world of two-handed citizens with double brain activity.
Although Jackson’s claims were based on scientific observation, they were eventually rejected. However, such ideas still exist, and some believe that learning to use the non-dominant hand can have a beneficial effect on brain activity. People making such claims are usually referring to neuroplasticity, which is the ability of the brain to change its structure and function in response to experience.
Take Whole Brain Power Consulting as an example, the “revolutionary brain training program” from Michael Lavery, who claims to be “a pioneer in applied neuroscience and brain function. ” Through a set of “simple ambidexterity, writing, and memory training,” he promises to “boost your mental circuits, your memory, beat stress, sharpen your mind, elevate your mood, improve sleep, and more.” and so on.”. And all this for only $67 (4400 r).
Various websites claim that practicing using your non-dominant hand can improve your creativity. In his Good Financial Cents blog, certified financial designer Jeff Rose claims that using the “opposite” hand to perform daily tasks like brushing your teeth will “strengthen the neural connections in the brain and grow new ones.” It also “helps your brain cells grow.”
Rose talks about how “the non-dominant hand is connected to the non-dominant hemisphere of the brain, something that we don’t exercise as much… So when you use the non-dominant hand, both hemispheres are activated, which can lead to a change in thinking and increased creativity.”
While the structure and function of the brain can, of course, be greatly altered by new experiences and training, and your brain does indeed continue to grow new cells throughout your life, the question of how ambidexterity affects brain function is still poorly understood. There is no scientific evidence that non-dominant arm training can lead to such positive effects.
While Rose correctly writes that the non-dominant hand is associated with the non-dominant hemisphere of the brain, his assumption that this hemisphere does not exercise as often is incorrect, since all behavioral scenarios, even those that activate areas of the brain that exist only in one of the hemispheres, activate both hemispheres.
Some neuroscientists believe that ambidexterity training can be harmful, based on some research showing that innate ambidexterity correlates with poorer academic and mental health outcomes. These studies show that ambidexters perform worse than left-handed and right-handed people on a variety of tasks, especially arithmetic, memory problems, and logic exercises, and that ambidexters have language problems and attention deficit disorder. Ambidexterity has also been linked to accelerated brain shrinkage with aging.
“The two hemispheres of the brain are not interchangeable,” says cognitive scientist Michael Corballis of the University of Auckland, who has done several studies on ambidexters and their academic success.