Announcer: Welcome to Stuff From the Science Lab from www.HowStuffWorks.com.
Allison Loudermilk: Hey, guys, and welcome to the podcast. This is Allison Loudermilk, the science editor at www.HowStuffWorks.com.
Robert Lamb: And this is Robert Lamb, a science writer at www.HowStuffWorks.com.
Allison Loudermilk: Today we are discussing one of my favorite articles, I think, on www.HowStuffWorks.com. This is one that you wrote.
Robert Lamb: Yeah, yeah. It's pretty good.
Allison Loudermilk: Back in the day. The title is actually "Are Lefties Better at Sports?" As you allude to in your intro of said article, lefties tend to think they're superior. In fact, you were saying that right before we started recording.
Robert Lamb: Yeah. I think I was criticizing you because you are, in fact, a lefty.
Allison Loudermilk: I am a lefty, and you are not.
Robert Lamb: Yeah.
Allison Loudermilk: Did you ever want to be a lefty?
Robert Lamb: No, because you're always bumping into things. You've got to have a special desk. It just looked kind of like a pain. My sister was a lefty, and my wife is a lefty.
Allison Loudermilk: Really?
Robert Lamb: It's kind of awkward because we have to watch how we sit next to each other at things. If we're at a dinner table next to each other, we might be bumping elbows. It's annoying. Then with left-handed people, whether there's on in the family or you marry one, there's the whole thing about them being evil. I'm always just hesitant when I'm around lefties.
Allison Loudermilk: That explains so much about our working relationship.
Left-handedness or right-handedness is just something that we inherit. In fact, lefties and righties have been around as far back as the Paleolithic period. In your article, you stated that the number of left-handers is roughly 10 percent of the population. That number has remained steady for about 10,000 years, which is pretty incredible.
Robert Lamb: Yeah, 10 percent.
Allison Loudermilk: Those cavemen, those unique lefty cavemen back in the day.
Robert Lamb: It probably wasn't too hard on those guys because they didn't have desks. They probably weren't eating at a dinner table.
Allison Loudermilk: They weren't having to use those annoying left-handed scissors.
Robert Lamb: What other products are there that are specific to left-handed. I just use regular products since I'm right-handed. I don't know what kind of special equipment you guys need to function.
Allison Loudermilk: There are mugs with special labeling so we can read them.
Robert Lamb: Mugs?
Allison Loudermilk: Yeah.
Robert Lamb: I have a mug on my desk right now. Why is that a right-handed person's mug? If it's left-handed, don't I just turn it around or s omething? Where else can you put the handle? Is it on the inside for lefties?
Allison Loudermilk: I don't know. I have a special left-handed mug. For instance, I'm looking at the pencil in my hand right now, just in case I need to take a note or two, and I cannot read the writing. However, if I hold it in my right hand, I can read the writing. That's not a big deal. I don't really need to read the writing on pencils all that often. It's just one of those things that we lefties have adapted to deal with.
Robert Lamb: The next time you go to buy a car or whatever and somebody gives you the business pen, and they give you one that's for right-handed people, you should get really offended and throw it back at them. That would be great.
Allison Loudermilk: Yeah. There is a whole lefty movement. I'm not talking about politics, obviously. So nature/nurture. What's the deal here? We're not really sure of the exact combination of genetic or environmental factors that contribute to what makes us right-handed or left-handed.
Robert Lamb: It is important to note that you do see this throughout the animal kingdom.
Allison Loudermilk: Definitely. You were talking about the sea snails in your left-handed article.
Robert Lamb: And the crabs. You see it. If you don't have hands, it's called what?
Allison Loudermilk: Laterality I believe. Yeah, so just the preference to do different bodily operations one way or another. In the case of the snails, for example, isn't about their shells? They coil counterclockwise, right?
Robert Lamb: That's right.
Allison Loudermilk: So that's what makes them a lefty snail. Even in the case of fish, where a lefty fish would probably dart left as opposed to a righty fish. If there's a predator chasing you, maybe that benefits you because they're not going to expect the fish to dart left, so it's a surprise move. On the other hand, if all the other fish are darting right, and you're just kind of out there hanging out in the ocean, maybe it doesn't benefit you. But we're not quite there yet.
Robert Lamb: We'll touch back on this in a second.
Allison Loudermilk: The question of whether you're a righty or lefty some think is settled in the womb, which I think is kind of interesting. Then you hear other people say that handedness isn't settled until as late as age 5 in humans. I think my son might be a lefty.
Robert Lamb: Do you think so?
Allison Loudermilk: I think so. I'm proud of the little guy. Yeah.
Robert Lamb: Are you going to take sides if one's right-handed and one's left-handed?
Allison Loudermilk: No, I will never be an evil parent and force him to write or do anything else he doesn't want to with the right hand or left hand. I'm not into that kind of parenting, Robert.
Robert Lamb: Okay.
Allison Loudermilk: There are some costs of being a lefty which I find really interesting, and which you guys have probably heard about. There's the big one about driving and accidents. Have you heard this, that lefties are more prone to being in accidents?
Robert Lamb: It's like the fish thing, right? You said the fish will dart one way when the others dark the other? Except this is behind the wheel of a moving automobile.
Allison Loudermilk: I've heard it explained as if you're left-handed, that's your dominant hand, so if you imagine them on the car wheel, you're more prone to turn the car into oncoming traffic. That's one way I've heard it explained. I have not seen any studies to back that up.
Robert Lamb: A smaller height is apparently another factor, though.
Allison Loudermilk: A smaller height.
Robert Lamb: My wife is pretty tall for a girl, so I don't know how much I buy that one.
Allison Loudermilk: And these are theorized costs of being a lefty.
Robert Lamb: Yeah, and they probably pan out over large populations, so you can't just be like, "Whoa, that's total BS because my wife is tall."
Allison Loudermilk: Also, later onset of puberty. They may not live as long, which is fine.
Robert Lamb: You don't care?
Allison Loudermilk: Yeah. Also, a higher instance of schizophrenia, alcoholism, dyslexia, along with stuff like Crohn's disease, and ulcerative colitis. Then you have some mental disabilities that may be showing up in lefties more. That about takes care of it for some of the costs out there of being a lefty, using your left hand with those funny green scissors.
Robert Lamb: That's the thing. That's probably pretty traumatizing, the funny green scissors, and the funky desks.
Allison Loudermilk: I will tell you that when you're learning sports, maybe you're learning how to shoot, you're learning archery, and the instructor has never dealt with a lefty, so they have to figure out how to show you with the arms, and they're right-handed, it can sort of get annoying after awhile.
Robert Lamb: How about playing guitar? I wonder if they have to use a different hand.
Allison Loudermilk: I would think so. You use your left hand to pick. I would use my left hand to strum the guitar, or whatever. Wouldn't you use your right hand?
Robert Lamb: You know how the older guitar dude always come on to the lady in the movie by showing her how to play the guitar? I wonder if that's a limiting factor if he's a righty and he's coming on to a lefty.
Allison Loudermilk: Good point. Definitely.
Robert Lamb: Let us know, guitar players, how that's going on for you.
Allison Loudermilk: There is one good thing about being a lefty. Whether you're smacking a tennis ball across court, or landing a left hook, or you're fighting someone in hand-to-hand combat, as the case may be, you're going to have that advantage of surprise, right?
Robert Lamb: Yeah. This is my favorite area of the study. I don't get to write about gladiatorial pits much at How Stuff Works.
Allison Loudermilk: Not nearly as much as you want to.
Robert Lamb: I would probably get bored of it if I was writing for the history beat because Lord knows it's just gladiator after gladiator article for those guys. But it comes down to this. Say you're especially in a primitive environment or an older culture before you had guns and all this, and it was more of a situation where I need to know how to either use my hands for combat or some sort of sword or club.
Allison Loudermilk: A machete.
Robert Lamb: Or a trident and a net. That's if you're in the gladiator pit. But yeah. It's hand-to-hand combat with some sort of weapon. A lot of times this is going to be your bread and butter. It's like a part of your culture where there's a lot of fighting in it, or you're regularly going to war, or your social status depends on it, so you're going to train, right?
Allison Loudermilk: Right.
Robert Lamb: In fighting you're going to lead with your left or right. If you're right-handed you're going to lead with the right. If 90 percent of the population is right-handed, who are you going to train to fight?
Allison Loudermilk: This brings up an interesting question.
Robert Lamb: Who are you going to train to fight? You're going to train to fight the right-handed people.
Allison Loudermilk: Yes, you are. Say you're a pro athlete. I'm sure lefty Oscar De La Hoya is not - or somebody who's fighting lefty Oscar De La Hoya is going to go into the ring with a left-handed fighter.
Robert Lamb: Exactly. They're going to train up, but knowing they're going to go in and fight that guy. Still, that's not like all of your training. How much of your training can you devote to that 10 percent versus that 90 percent?
Allison Loudermilk: I totally get that. Is it a one-time occurrence? Is it a limited occurrence versus regularly going up against right-handed? I get that. Definitely.
Robert Lamb: The other benefit, of course, is if you're the left-handed dude -
Allison Loudermilk: Or gal, as the case may be.
Robert Lamb: Or gal, then you're pretty much always going to have that advantage.
Allison Loudermilk: I do. I totally do. Ping pong, I rock.
Robert Lamb: You're still going to be training to fight or play against the 90 percent of the people who are right-handed, but you're always going to carry that left-handed advantage in except the 10 percent - well, even the 10 percent that are lefties. Most of their training is going toward righties as well. You're going to always have a certain amount of advantage over the guy on the other end of the court or gladiator pit.
Allison Loudermilk: Indeed. Tell us what happened with these French researchers who checked out this phenomenon.
Robert Lamb: This was an awesome study. This took place back between 2001 and 2004. These French researchers decided to test this theory of lefty battle superiority.
Allison Loudermilk: Right. They were from the University of Montpellier.
Robert Lamb: Yes. Mont-feel-ier, I believe. That's the way I always heard it when I was living in Canada. Correct me if I'm wrong, Canucks. Basically they were like, "Let's study this," but instead of watching tennis players or whatever - because sports is just sort of a deviation from killing people with their bare hands.
Allison Loudermilk: Certainly. Definitely.
Robert Lamb: There's no doubt about that at all. I think everybody can pretty much agree that sports are like war of life.
Allison Loudermilk: Yes. Warfare evolved.
Robert Lamb: People tune into sports, but if war was on the other channel, they would totally tune in to war. They decided, "Where can we really put this theory to the test?" They decided to go to the places where they had really high murder rates and people were more likely to commit these murders s handheld weapons, their hands, etc.
Allison Loudermilk: They're visiting societies without the infiltration of guns, somewhat simple societies.
Robert Lamb: Right. And in these societies, again, the left-handed person would seem to have the advantage and would seem better prepared to survive these violent encounters. Sure enough, the rest of the world, 10 percent of the population lefties. In these areas, they found as high as 27 percent lefties.
Allison Loudermilk: Okay.
Robert Lamb: That means there's enough violence going on that the lefty population, the percentage of the population that was lefty, was higher because they're surviving more violent encounters than they're losing out in.
Allison Loudermilk: Right. So there's a correlation between the high murder rate and the occurrence of left-handedness in those societies.
Robert Lamb: Yeah.
Allison Loudermilk: That's pretty interesting. I was looking at the data in the paper. If you want to read the paper, you should look it up. Charlotte Faurie, she has all of her publications on her CV on the web. You can find the paper itself by her and her coauthor, Michel Raymond, and it was published in Proceedings of the Royal Society. It had a nice title. That was "Handedness, Homicide, and Negative Frequency-Dependent Selection."
Robert Lamb: I'm just really hoping for the day we can get that left-handed percentile down to like 5 percent. Just think how safe the streets will be.
Allison Loudermilk: I know, right? Here's another theory for you n why lefties might kick butt in sports. This comes from freelance writer Julia Layton. She wrote an article for How Stuff Works on whether left-handers are quicker thinkers than righties.
Robert Lamb: This is more in the brain of where it's happening. It's fast decision making on the court or battlefield.
Allison Loudermilk: Um hm. The theory goes something like this. According to Julia, the two hemispheres, or halves of the brain, the right and left, are pretty much identical.
Robert Lamb: Okay.
Allison Loudermilk: For the most part. They process the same information with data traveling between them via this nice neural roadway, pathway. Language processing, however, tends to take place in one hemisphere or the other, and it's often the left hemisphere. But for left-handed people, it can actually take place in both hemispheres.
In addition to language processing, sensory data processing often goes to one hemisphere or another. Say the data picked up on the right side of the body, whether it's with the right eye, the right ear, or even the right hand or the right foot, you get the idea, it's going to go to the left hemisphere for processing and vice versa. Data picked up on the left side goes to the right hemisphere. I don't know why they have to make this so complicated. Why couldn't the left side and the left brain line up and the right side...but anyway. What's up with this criss-crossing business?
Robert Lamb: It kind of makes sense. Imagine swiveling into something on angles.
Allison Loudermilk: How does this relate to the title of our podcast, which is "Are Lefties Better at Sports?" If you think that people who write with their left hands may be better at processing sensory information and language with both hemispheres of their brain, then maybe they're better at handling all that information in a fast fashion.
Robert Lamb: Yeah. You've really got to be like that out there.
Allison Loudermilk: And I am like that.
Robert Lamb: Yeah. On the tennis court.
Allison Loudermilk: Can we get a snapping sound in there? How do you test this? It's nice for me to spout off about how lefties are superior, but let's take it to the lab.
A bunch of guys from Australia National University did. They got together 100 people: 80 righties and 20 lefties, and they tried to test the flow of info between the two sides of the brains. The paper was published a few years back in the journal Neuropsychology if you're interested.
Here's how they tested it. They showed participants a dot on a com puter screen. Sounds really fascinating so far.
Robert Lamb: Dot on a computer screen. Okay.
Allison Loudermilk: Yep. The computer screen had a dividing line down the center.
Robert Lamb: So it's kind of like Pong.
Allison Loudermilk: Yeah. You see a dot. It would appear to the left or the right of the dividing line. Then you, the participant, had to press a button to indicate which side the dot showed up on.
Overall, when the dots were appearing on the left and the right-hand side, lefties were faster at this task. But change it around and just put the dot on one side, and righties were faster. Extrapolating from this, righties could be faster at processing info that targets just one side of the brain, but lefties would be faster, according to this experiment, in targeting both types of information.
Robert Lamb: Okay.
Allison Loudermilk: Let's take it back to sports. Again, like we kind of said in the beginning, if lefties are indeed better at processing sensory info with the two hemispheres, they could have a slight advantage in sports, gaming, other activities. I bet you kind of wish you were a lefty if it's going to make you a better gamer, huh?
Robert Lamb: It's not about being a great gamer. It's about enjoying the video game experience.
Allison Loudermilk: Right. It's not about the competition.
Robert Lamb: Sure.
Allison Loudermilk: Do you really believe that?
Robert Lamb: I do believe that. Yeah. I think there are two schools of thought. There are people who play games and are really good at games. Then others who want to enjoy the storytelling aspect of it. There's still games that I'm probably one of the best in the world at.
Allison Loudermilk: Really? You want to name some of those?
Robert Lamb: Yeah, actually. There's a game called Virtual Pro Wrestling 2 that came out for N64. I could probably beat just about anybody.
Allison Loudermilk: Ooh! Listeners, if you're out there, I dare you to challenge Robert on this.
Robert Lamb: You'd have to come to my house and play it. It's not online or anything. It's really hard for me to back that up.
Allison Loudermilk: So it's just an idle claim.
Robert Lamb: No, I firmly believe that I've wasted way too much of my life playing a game. It probably is going to pay off if somebody comes to my house for a throw down.
Allison Loudermilk: Let's get back to the study for a sec. To reiterate, if lefties are indeed better at processing sensory info with those two hemispheres, they could have the advantage in sports. Theoretically, they could use both hemispheres of the brain to manage that stimuli.
Robert Lamb: Yeah. The thing that's coming to my mind is I'm imagining a dude on a football field. Instead of one guy coming at him from one direction, it's like two guys coming at him. He's better able to process both of these guys.
Allison Loudermilk: Plus the ball, and he manages to catch the ball.
Robert Lamb: A football field especially seems like a situation where you'd have all sorts of stuff going on.
Allison Loudermilk: The crowds roaring in your ears. It's kind of like "Friday Night Lights." Have you ever seen that show?
Robert Lamb: I know of it, but I've never seen it.
Allison Loudermilk: The last thing I want to say about lefties outside of sports, this study was eventually talking about - they said that being a lefty could also benefit you in old age. The idea is that with a greater ability from one brain hemisphere to quickly back up the tasks of the other, that left-handed seniors could retain mental quickness longer than their right-handed counterparts.
Robert Lamb: That's cool.
Allison Loudermilk: But I would keep playing Sudoku, or whatever it is, to keep up that mental acuity.
Robert Lamb: Just don't let them get behind the wheel because they're still going to want to go into oncoming traffic.
Allison Loudermilk: Right. So if you're old and a lefty, you're in trouble.
Robert Lamb: This was a great podcast, especially for the lefties, because it gives you so much fuel to just go out there and talk about how great you are.
Allison Loudermilk: I've been wanting to do this podcast forever. We'd love to hear from you, your thoughts, all the lefties out there, some of the righties perhaps - just a few though. If you want to write in, send us an email to ScienceStuff@HowStuffWorks.com. We also have some listener mail going on.
Robert Lamb: Yeah, we do. Are you reading, or am I reading?
Allison Loudermilk: I think I might do the honors.
Robert Lamb: Go for it.
Allison Loudermilk: This listener mail is from Valerie. Val works at a prosthetic company. She manufactures prosthetics.
Robert Lamb: Oh, prosthetic limbs. Cool.
Allison Loudermilk: She wrote in to say, "Thank you guys so much for doing your prostheses podcast. I work as a prostheticist. Pronounce that carefully if you don't want to sound like a 'lady of the evening.'" She was saying that when we were talking about some of the par-Olympians - we were talking about that. We were kind of putting it out there, where par-Olympians could eventually be surpassed, people who have all their limbs.
Valerie was breaking it down to a matter of energy return. What she said was that an anatomical human leg can return 130 percent to 200 percent of the energy easily. The problem here is that until we can figure out how to get that with a prosthetic limb, you're only getting 99.99 percent energy return. This is actually what led - what was his name? Oscar? To qualify.
Robert Lamb: The dude with the really awesome -
Allison Loudermilk: The cheetah blades.
Robert Lamb: The cheetah blades.
Allison Loudermilk: Yeah. In South Africa. He's not getting that energy return yet.
Robert Lamb: But once they're able to engineer that and equal the energy efficiency of human limbs, then -
Allison Loudermilk: Ixnay. Yeah. Valerie also wrote, "As for the cost, yes, the new fancy ones are very dear, but for vets returning home from the wars, everything they need is 100 percent paid for." which is surprising and great news if that's the case.
Robert Lamb: Yeah. I think there was a part in The Wire, like the last season where they dealt with dudes getting prosthetics.
Allison Loudermilk: She was also writing that most new developments in prosthetics can be tracked to wars. World War II equaled improvements in knee and modular components. Vietnam equaled improvements in myoelectrics. Iraq/Afghanistan targeted re-enervation and the Darpa hand.
Robert Lamb: That one's a really cool one. basically, if you are in the business of sending your citizens off to become maimed in a war, you want to send the message that A) We will do everything we can possibly do to make life easier when you come back without that hand, and also, you don't want all your veterans standing around with no legs because it kind of looks bad for new recruits. Seriously. You don't want people sitting around on boards with missing limbs.
Allison Loudermilk: Right.
Robert Lamb: If you've got a nice government-funded artificial leg, you're not even going to tell the difference.
Allison Loudermilk: Yeah. We also heard from Jeremy. Jeremy used to work for a company that made dental implants. He was talking about osseointegration. Do you remember what osseointegration was?
Robert Lamb: That's where titanium and bone, fusing them together.
Allison Loudermilk: Yeah. He was saying that for some of the dental implants he was working on, it took over six months to fully integrate, but the newer designs got this time down to less than three months to fully integrate.
What the mechanisms was that was at work to speed up the integration was you douse the surface in an acid bath to rough it up and make it easier for the bone to integrate with the implant.
That was really interesting. If the process wasn't occurring fast enough, you can dump some acid in there and speed it up.
Robert Lamb: Huh. I'll have to ask my dad about that. He's a dentist.
Allison Loudermilk: Thanks, Jeremy for writing. Lastly, we heard from Amy Claire, who wanted to let us know that our prosthetic podcast reminded her of a Flannery O'Connor story she just finished reading for her lit class.
Robert Lamb: Oh yeah. I always get the titles confused.
Allison Loudermilk: Good Country People.
Robert Lamb: I was about to say A Good Man Is Hard to Find, but that's a different story.
Allison Loudermilk: Yeah. If you guys have anything to say, again, send it our way, or connect with us on Facebook. We're StuffFromTheScienceLab. On Twitter, we're LabStuff.
Robert Lamb: Check us out there. we'll keep you updated on what our latest podcasts are about, what we're blogging about, odd news stories that come our way, as well as the new articles that are hitting the How Stuff Works website itself.
Allison Loudermilk: All right. Thanks for listening.
Announcer: For more on this and thousands of other topics, visit www.HowStuffWorks.com. Want more How Stuff Works? Check out our blogs on the www.HowStuffWorks.com home page.