Everything Everywhere Daily: History, Science, Geography & More - Righties vs Lefties

Episode Date: September 25, 2021

Statistically speaking, about 90% of you listening to my words right now are right-handed. Of the rest of you, almost all of you will be left-handed. The question of why so many more people are right-handed as opposed to left-handed is one that people have asked for centuries. It is an imbalance that has existed throughout history and across every culture. Learn more righties and lefties and why the imbalance between them exists, on this episode of Everything Everywhere Daily. Learn more about your ad choices. Visit megaphone.fm/adchoices

Statistically speaking, about 90% of you listening to my words right now are right-handed. Of the rest of you, almost all of you will be left-handed. The question of why so many more people are right-handed as opposed to left-handed is one that people have been asking for centuries. It's an imbalance that has existed throughout history and across every culture. Learn more about righties and lefties and why the imbalance between them exists on this episode of Everything Everywhere Daily. Do you ever climb into bed ready to sleep only to have your mind

start racing the moment your head hits the pillow? Thoughts bouncing around, replaying the day or jumping ahead to tomorrow? That is exactly why Catherine Nikolai created Nothing Much Happens. Each episode is a gentle, cozy bedtime story where, well, nothing much happens. No drama, no tension. Nothing you need to follow closely. Just soft narration, calming repetition, and soothing sensory details designed to help your mind slow down and your body relax.

It's not about entertainment, it's about rest. And millions of listeners around the world use it. every night to quiet their thoughts and finally fall asleep. If you've ever struggled to shut your brain off at night, this might be exactly what you've been missing. You can listen to Nothing Much Happens wherever you get your podcasts. Episodes are every Monday and Thursday. This episode is sponsored by the Travel Photography Academy.

If you've listened to enough episodes of this podcast, you'll notice that I often interject places that I've visited. That's because I spent over 10 years of my life traveling around the world almost nonstop. During that time, I went from being a complete novice in photography to winning almost every major travel photography prize in North America. When I learned how to do travel photography, I had to do it the hard way. It took years of time and lots of travel. That's why I created the Travel Photography Academy, so you can learn from me in much less time, spending much less money. It's an online video course which I shot on location in France, Spain, and the United States,

and I cover everything you need to improve your travel photography. So, if you want to take your photography to the next level and get better photos on your next trip, visit travelphotographyacademy.com or click on the link in the show notes. The issue of hand dominance is a really weird one. If hand dominance were totally random and there was a 50-50 split in right and left-handed people, that would kind of make sense. It would be like sex selection at conception. Everyone is assigned their sex at conception completely randomly based on genetics.

If hand dominant were 100%, that too would kind of make sense. All humans have eyes, ears, nose, and feet. If everyone had the same hand dominance, it would just be another part of being human. However, neither one of those is the reality we live in. It's neither a random nor universal. The number usually given for the percentage of people who are right-handed is about 90%. The remaining 10% of left-handed people are a minority, but not so small of minority as to be chalked up to a genetic defect.

FYI, for the purposes of this episode, I'm going to ignore people who are ambidextrous or mixed-handed. Ambidextrous people can use either hand equally well, and mixed-handed people use one hand for some things and their other hand for other things. Those are both real things, but their numbers are so statistically small that it isn't worth constantly bringing up. They are around or under 1% of the population. Surprisingly, the percentage of the population, which is right or left-handed, isn't universally agreed upon.

The number that I'm going to use for the purpose of this episode, and the number which comes up most often is 90%. I've seen numbers as high as 95% and as low as 70%, which seems like a really wide range, considering that it's something that should be rather easy to calculate. That being said, here's what we do know about handedness. First, right-hand dominance goes back a very long time. Cut marks and wear marks on stone tools indicate that most people were right-handed when they made them. Also, the wear-on teeth and homo-habelous fossils indicate that when something was held in their teeth, it favored those who were right-handed. Also, when full human or ancestral human skeletons are found, the right arm is often slightly larger than the left, indicating that it got more use and they were right-handed.

Moreover, this right-handed preference seems to be more profound over time. The evidence from human ancestors from 1.5 million years ago shows weak support, but 600,000 years ago, the evidence is quite abundant. So this isn't a recent development. Second, the preference for right-handedness seems to be universal for humans. There are no civilizations, tribes, or groups of people that we have ever found that are mostly left-handed. Up until recently, left-handed people just had to deal with, living in a right-handed world. Very few things were built to accommodate left-handed people.

Take, for example, ancient warfare. A soldier would have to have a shield on one hand and a sword or spear in the other. You had to have your shield in your left hand, regardless of which hand was dominant, because you had to be in a line with other soldiers. Everyone had to line up with swords and shields on the same hand or the formation wouldn't work. Throughout the 19th and early 20th centuries, If you were left-handed, you just had to learn how to use scissors and other tools built for right-handed people. Likewise, most children were just forced to write with their right hand. The historical attitude towards left-handed people can be summarized by the fact that the Latin word for left is sinister, because we all know left-handed people are evil.

By the same token, the Latin word for right is dextera, which is the basis for the English word dexterous. The word for being good at manual manipulation with your hands comes from being wrong. right-handed. The word right is also synonymous with being correct or ethically sound. The Bible talks of being seated at the right-hand of God, which is the position of favor. So, why do we have this imbalance between right-and-anded people? The first place to look would obviously be genetics. Since the discovery of DNA and genes, it's given us insight into many parts of what makes us human. The problem is, no one has ever found a gene that could be the handness gene. Moreover, handiness doesn't behave like normal recessive or dominant traits.

Two left-handed people actually do have a slightly higher odds of having left-handed children. The odds are 25% instead of 10%, but it's still smaller than average. Both of my parents are left-handed, but my brother and I are both right-handed. If there is a genetic component, it would have to be several genes working in conjunction with each other. There are many cases of identical twins where one is right-hand. right-handed and one is left-handed. In fact, it occurs 21% of the time. Given that they have identical genetics, that should be impossible if genetics were the only cause. And here I'll point out, there's a slight difference between the sexes when it comes to being left-handed. Men are about

12% left-handed versus women who are 10% left-handed. It's a small difference, but the difference is real and has been repeatedly found. And no one knows why. If it isn't genetic, then maybe it's cultural. Perhaps it was something that was passed on between early humans, which somehow just became part of us today. This is highly unlikely as well, given that children often develop a hand preference before they start learning. If there was a cultural component, then it's likely we would have at least found one group of people somewhere that was predominantly left-handed, but we never have. The most popular theory right now is that hand dominance is due to the brain. Our brains look symmetrical, but they behave very asymmetrical.

symmetrically. One of the things that happened to early proto-humans between 1.5 million years ago and 600,000 years ago was the development of language. Language and motor skills are both controlled in the left side of the brain. The left side of the brain controls the right side of the body and vice versa. As that side of the brain is dealing with motor skills, it might just be easier for our brain to prefer the right-hand side because that's what's being controlled. Chimpanzees are one of the closest species to humans. They normally show no preference for one side or the other. When they walk upright, however, they can show a preference, but the side they choose is equally distributed. In fact, no species of Simeon shows any hand preference whatsoever. What's the biggest difference between humans

and monkeys and apes? We have language. Another theory is that the brain may develop a preference in the womb due to some sort of stress, which is why you see one and five identical twins who have different-handedness. The truth of the matter is, no one is really totally sure why some people are right-handed and some people are left-handed. Being left-handed is a bit of a mixed bag. There are a few downsides. The most obvious is that almost everything in the world is designed for right-handed people. Everything from kitchen gadgets, tools, and musical instruments are all usually designed for right-handed people. Moreover, left-handed people have higher rates of certain disorders, including dyslexia and schizophrenia. They also have higher rates of autism, depression, and bipolar disorder. And they suffer

from higher rates of breast cancer, heart disease, and bone fractures, which seemingly have absolutely nothing to do with handedness. There is a flip side, however. Left-handed people tend to perform better intellectually. On average, they score one point higher on IQ tests. They are also significantly overrepresented in professional orchestras, mensa, and gifted programs. They also tend to score better on tests such as the SAT and the LSAT. There have been eight left-handed U.S. presidents, which is double the rate that would be expected from the general population. Left-handed athletes also tend to perform better than their right-handed counterparts. This is mostly thought to be due to the fact that people aren't used to facing left-handed opponents.

Left-handed boxers do well for this reason, as do left-handed tennis players. Martine de Verratilova, Rafael Nadal, John McEnroe, Rod Laver, Monica Sellis, and Jimmy Connors were all lefties. Left-handed baseball pitchers are prized because they have an advantage. However, you almost never see left-handed catchers. The last left-handed catcher in the major leagues was Benny Di Stefano, who played in 1989. Likewise, there are almost no left-handed quarterbacks. Tuoethevaloa, who plays for the Miami Dolphins,

is the first left-handed quarterback to play a single down in the NFL since 2015. This mostly has to do with the fact that how a quarterback throws has implications for the entire team. A quarterback will usually run in the direction they are throwing, which means that the offensive line will have to behave differently to protect a quarterback's blind side, i.e. the hand they don't throw with. In conclusion, we don't really know why some people are left-handed and some people are right-handed. It probably has something to do with the brain, and maybe there's a genetic component, and maybe it has something to do with development in the womb. Regardless of why it happens, just make sure that you keep your eye on any left-handed people you know. I've been

told that they're all sinister. The associate producers of Everything Everywhere Daily are Peter Bennett and Thor Thompson. If you'd like to support the show, please join the list of patrons over at patreon.com. And also remember, if you leave a review or send me a question, you two can have it read on the show.