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Why Do Lefties Exist? · Stuff You Should Know

0:01
Speaker 1: Welcome to Stuff you Should Know from House Stuff Works
0:04
Speaker 1: dot com. Hey, I'm welcome to the podcast. I'm Josh
0:13
Speaker 1: Clark with Charles W Chuck Bryant and Jerry's over there too,
0:18
Speaker 1: and this is stuff you should know the podcast. Man,
0:22
Speaker 1: oh man, I would love for people to just lie
0:26
Speaker 1: on the wall in the studio. Sometimes get squashed. There's
0:31
Speaker 1: a lot of fun prerecord today. People. I hate that
0:34
Speaker 1: you miss out on that kind of stuff. But you
0:35
Speaker 1: know what, that's a that's for us. We we deserve
0:38
Speaker 1: a little something. Yeah, and that's called pre show fun, fun,
0:44
Speaker 1: hammering out the details, hammering other details. I thoroughly enjoyed
0:49
Speaker 1: researching this one. Oh really, it burned my brain a
0:52
Speaker 1: little bit. It burned my brain a little bit too,
0:53
Speaker 1: But um, I just I didn't know anything about handedness
0:58
Speaker 1: and uh no not don't use your hands much. Well,
1:01
Speaker 1: I mean as far as, uh why you are left
1:04
Speaker 1: or right handed or ambidextrous. It was all kind of
1:06
Speaker 1: new information for me. I feel like I had read
1:09
Speaker 1: that Io nine article, which we should give a huge
1:12
Speaker 1: shout out because it was forming partially the basis of
1:15
Speaker 1: this UM episode. Yeah, why are so few people left handed?
1:19
Speaker 1: From Io nine and they sourced a lot of great
1:22
Speaker 1: stuff from Discover magazine and their articles, so and science
1:26
Speaker 1: and science, so it's legit. It is legit. Uh, possibly
1:30
Speaker 1: even to legit to quit yeah, yeah, which I could
1:35
Speaker 1: not do with my left hand. I guess I can't.
1:37
Speaker 1: I just did it. You just did to your science
1:40
Speaker 1: sign signing to me. I'm equally bad at at doing
1:46
Speaker 1: too legit to quit finger motions with either hand. I'm
1:49
Speaker 1: right handed, by the way, what about you, I'm right handed,
1:52
Speaker 1: but that is weird since you have your mc hammer
1:54
Speaker 1: pants on. I thought you would be good at that.
1:56
Speaker 1: That's all just it's not hard to put on pants.
1:59
Speaker 1: It's hard to do too legit a quit finger motions. Yeah,
2:01
Speaker 1: I'm right handed. Um to well, I was about to say,
2:04
Speaker 1: to a fault, but heavily heavily right handed, because after
2:08
Speaker 1: reading this, I do believe that there is a bit
2:10
Speaker 1: of a spectrum. I think, um oh yeah, yeah. I think.
2:15
Speaker 1: I think some people are way dominant with their one hand,
2:18
Speaker 1: and some people skew more towards you. I can do
2:20
Speaker 1: some things with this hand, uh, And some people are ambidexterous,
2:24
Speaker 1: which we'll talk about. Very few, though fewer than you. Think, yeah,
2:27
Speaker 1: But um, I am heavily, heavily right handed. I cannot
2:30
Speaker 1: do many uh what's the word I'm looking for? Um? Fine,
2:38
Speaker 1: not like my fine motor skill tasks. I cannot do
2:42
Speaker 1: very well with my left hand. I can just like
2:44
Speaker 1: club things and smack things and knock stuff over, knock
2:47
Speaker 1: stuff over like Frankenstein clearing a table pretty much. What
2:51
Speaker 1: about you? And can you do anything with your left hand?
2:54
Speaker 1: I used to think I was, you know, pretty much
2:57
Speaker 1: just strictly right handed, But then i've it's especially researching this,
3:01
Speaker 1: I paid attention, and I'm like, no, I used my
3:03
Speaker 1: my left hand a little more than I thought. I'm
3:05
Speaker 1: definitely not ambidextrous. And if there is such a thing
3:08
Speaker 1: as a dominant hand, it's clearly my right. But this
3:10
Speaker 1: this article points out, or actually it was a science
3:14
Speaker 1: m article that said, there's there's this idea that there
3:18
Speaker 1: isn't a dominant hand, that you have uses for both hands,
3:22
Speaker 1: and one kind of specializes in one thing and one
3:24
Speaker 1: specializes in another. And the the example they used to
3:27
Speaker 1: illustrate that was, um, cutting like meat with a fork
3:31
Speaker 1: and knife. Yeah, I was gonna ask you about that,
3:33
Speaker 1: you know, Like I was thinking about I was like, oh, yeah,
3:35
Speaker 1: I guess I do use the knife pretty well with
3:37
Speaker 1: my left hand. I thought, crazy, No, my fork is
3:40
Speaker 1: in my left hand, my knife is in my right hand.
3:44
Speaker 1: And then I switched the fork over to my right hand.
3:46
Speaker 1: That's what I did too. I was gonna ask you that.
3:48
Speaker 1: So I'm definitely right handed, but you know my left
3:51
Speaker 1: hand does a great job holding the steak in place
3:54
Speaker 1: with my fork while I cut it with the knife. Yeah. Well,
3:56
Speaker 1: I'll come to think of it, though, I play guitar
3:58
Speaker 1: in drums, so I mean I have some left hand skill,
4:01
Speaker 1: I guess. Um. And I know if you break your
4:04
Speaker 1: dominant hand, you're gonna learn pretty quickly how to adapt.
4:09
Speaker 1: So it's possible to learn, uh, if forts to. It's
4:12
Speaker 1: all very interesting to me. It is, and we should say,
4:15
Speaker 1: if you happen happen just randomly to be listening to
4:18
Speaker 1: this episode on August thirteen, Happy National Left Handed Day,
4:25
Speaker 1: I looked out. When I looked that up, I was like,
4:26
Speaker 1: I wouldn't it be one of those another stuff you
4:28
Speaker 1: should know coincidence If this was happened to be released, No,
4:32
Speaker 1: not even close. Um. And it's good that left handed
4:36
Speaker 1: people have their own day because they've been fairly maligned
4:39
Speaker 1: throughout the millennia. Yeah, let's talk about that. Actually, okay,
4:44
Speaker 1: Um throughout history. In fact, even if you look at
4:47
Speaker 1: the words uh throughout history, there is a you know,
4:52
Speaker 1: uh the poopoo left handers. Basically like the word l
4:56
Speaker 1: y f T left yeah from Anglo Saxon means weak
5:01
Speaker 1: and the words where the word left comes from and
5:03
Speaker 1: the word sinister from Latin is the word for left. Yeah.
5:07
Speaker 1: Anybody who saw that episode of The Simpsons where Ned
5:09
Speaker 1: Flanders opens the left Toorium knows that because because I
5:13
Speaker 1: have a sinister reason to invite you all here sinister
5:18
Speaker 1: meaning left handed man. And that was when he announced
5:21
Speaker 1: the Leftorium. That show was so smart, you know, very smart.
5:24
Speaker 1: So many of those jokes like just flew over my
5:26
Speaker 1: head back in the day, Well, they're coming back to roost. Uh.
5:31
Speaker 1: There's a long list of um countries who have languages
5:36
Speaker 1: that link the word right with being good uh and
5:40
Speaker 1: the left with being bad or wrong uh. And in
5:44
Speaker 1: some countries even making hand gestures with your left hand
5:47
Speaker 1: is a no no. Well, and a lot of countries
5:51
Speaker 1: are a lot of cultures that eat food with their hands.
5:54
Speaker 1: Then utensils. Um. Using the left hand to eat or
5:58
Speaker 1: do a lot of things with is considered taboo because
6:00
Speaker 1: the right it's exactly right. You use the right hand
6:03
Speaker 1: to eat with, use your left hand to wipe with
6:05
Speaker 1: right and um, I think if you pay attention and notice,
6:09
Speaker 1: I'll bet you have a hand that's dominant and that
6:13
Speaker 1: that um activity wipe in your butt. Yeah, yeah, I'm
6:16
Speaker 1: alrighty are you? Yeah? Okay? But if you if you
6:20
Speaker 1: try the other hand, it will feel very weird. Whatever
6:24
Speaker 1: whatever hand you use normally, it's gonna feel weird if
6:27
Speaker 1: you use the option, and you'll just send it very messy. Sure.
6:31
Speaker 1: I wonder if you had a subconscious thing like you know,
6:33
Speaker 1: I was just eating these candy pecons with my right hand,
6:36
Speaker 1: and I know I'm gonna go back and eat them
6:37
Speaker 1: with my right hand. Oh, I don't even use my
6:39
Speaker 1: hands to eat them. I'm a little too germ conscious.
6:42
Speaker 1: I scoop food up in the crook of my elbow,
6:45
Speaker 1: which is very clean because it doesn't come in contact
6:48
Speaker 1: of other stuff, and then I eat out of the
6:49
Speaker 1: crook of my elbow. That's pretty funny. Um. So why
6:54
Speaker 1: have people been I mean, why have they picked on
6:57
Speaker 1: left handed people. There are some theories that is just
7:00
Speaker 1: a minority. You know, ten of people are left handed,
7:04
Speaker 1: and throughout history minorities have been picked on. That's right,
7:07
Speaker 1: this one thing, Um, there's there's at least a couple
7:10
Speaker 1: of cultures that equate left handedness with clumsiness. Yeah, that
7:14
Speaker 1: makes sense to me. Some hypotheses theorized that UM tools
7:20
Speaker 1: tool making for a very long time, UM has been
7:24
Speaker 1: done following right handed techniques. Still is in many cases, sure, um.
7:29
Speaker 1: And so when a lefty was trying to make tools
7:32
Speaker 1: or do whatever using right handed tools, they would have
7:35
Speaker 1: been clumsy with them. And therefore the idea that left
7:39
Speaker 1: handed people were clumsy or weak or whatever could have
7:42
Speaker 1: developed and carried on. Yeah, like, uh, colonial day, dad
7:46
Speaker 1: is teaching his two sons. Let's go with the son
7:49
Speaker 1: and a daughter. Even, let's how to use a saw.
7:53
Speaker 1: And you know, the son's left handed and he keeps
7:55
Speaker 1: he can't saw well, so the dad's just like he
7:58
Speaker 1: favors the daughter because she's you know, she's better with
8:01
Speaker 1: the saw. It's just it's easy to see how that
8:03
Speaker 1: could happen. Like he's mad at Roger but pleased with
8:05
Speaker 1: Prudence because prudence. She's always sawing things. Well, that's a
8:10
Speaker 1: colonium name, right, Yeah, sure, well I feel like it is. Okay,
8:14
Speaker 1: well what else is there? Who? Goody? Uh, goody, Alice. Okay,
8:20
Speaker 1: it's timeless. Um, but there's still that if you're lefty today,
8:25
Speaker 1: you might be frustrated with things like scissors and can
8:27
Speaker 1: openers and spiral notebooks and things that sort of U
8:32
Speaker 1: favor the right handed. Yeah, we're sitting next to a
8:35
Speaker 1: right handed person at dinner. The elbow thing, it's the worst.
8:38
Speaker 1: It's because there's so few left handed people. If you're
8:42
Speaker 1: planning a dinner party, first of all, it's just common
8:44
Speaker 1: courtesy to know the handedness of all of your guests,
8:48
Speaker 1: and then to put the appropriately right to put the
8:50
Speaker 1: left handed person at the end of the table so
8:52
Speaker 1: that their left hand is their left elbow is off
8:56
Speaker 1: the table and they don't have to worry about bumping
8:57
Speaker 1: into other people. Yeah, my mom is left ended, my
9:00
Speaker 1: father is right handed, and you came out right handed. Yeah, crazy,
9:06
Speaker 1: I sure did so. Um. Despite everybody knowing that there's
9:11
Speaker 1: a right handedness and a left handedness, it turns out,
9:15
Speaker 1: after investigating this kind of thing, science is really baffled
9:20
Speaker 1: as to what exactly is going on, why we would
9:22
Speaker 1: have handedness, yeah at all, where it comes from. Why
9:26
Speaker 1: the proportions seem to be steady. There's a lot of
9:30
Speaker 1: questions that you know, come up when you look into handedness.
9:35
Speaker 1: Whereas you know the average person who just kind of
9:37
Speaker 1: take it for granted, but no, not the average scientists. No, no, no.
9:41
Speaker 1: There are a lot of interesting theories though. UM. One
9:45
Speaker 1: is is that, uh, as we all know, we have
9:48
Speaker 1: a left hemisphere in the right hemisphere of our brain,
9:51
Speaker 1: and we are one of the only mammals that are
9:54
Speaker 1: very much UM have a it's called brain lateralization when primarily,
9:59
Speaker 1: and this isn't a cross the board, but primarily one
10:01
Speaker 1: hemisphere controls certain things and the other controls other things.
10:04
Speaker 1: And that is primarily controlling the opposite side of the
10:07
Speaker 1: body as the hemisphere. UM. But language and um controlling
10:14
Speaker 1: your you know, fine motor skills like things you do
10:16
Speaker 1: with your hands and your fingers. I have often been
10:20
Speaker 1: linked because uh, they are generally on linked together and
10:25
Speaker 1: on one hemisphere of the brain right for for the
10:28
Speaker 1: most part, people who are right handed. They make up
10:30
Speaker 1: the vast majority of human beings by the way. Yeah,
10:34
Speaker 1: I saw as low as seventy, but nothing lower than that,
10:36
Speaker 1: you know, eighty didn't Yeah, you're right, sorry, exactly. Um,
10:43
Speaker 1: those people have their language center in the left hemisphere,
10:46
Speaker 1: and I guess also their motor cortex in the left hemisphere,
10:50
Speaker 1: and the know the left and the U. There's a
10:56
Speaker 1: lot of questions about why this would be when the
10:58
Speaker 1: brain supposedly is a is always looking for efficiencies as
11:02
Speaker 1: much as possible. So they're saying, okay, well, these are
11:05
Speaker 1: two very human activities speech language and using your fingers
11:11
Speaker 1: to do stuff, right, So, um, they're also some of
11:15
Speaker 1: the more complex activities that humans engage in. So it
11:18
Speaker 1: makes sense that you just leave it up to one
11:20
Speaker 1: side of the brain so that these things can um
11:24
Speaker 1: not have to cross over the corpus colossum. Yeah, it's
11:27
Speaker 1: it's just a cluster together. It makes sense. It does
11:29
Speaker 1: make sense, but it's also a pretty thin explanation. If
11:33
Speaker 1: you you could also say the other the exact opposite,
11:36
Speaker 1: that it would make more sense that our motor skills
11:38
Speaker 1: and our language skills would be in opposite sides of
11:41
Speaker 1: the brain to give each other a break, rather than
11:43
Speaker 1: just weighting it down on the same side. The point is, though,
11:47
Speaker 1: as if you crack open a human brain and you
11:50
Speaker 1: look for the motor cortex and the language region, the
11:54
Speaker 1: language center, you're gonna find them most likely, statistically speaking,
11:58
Speaker 1: on the left hemisphere. Hence more right handedness. Right because
12:03
Speaker 1: of what you said that um that brain literalization where
12:06
Speaker 1: stuff that's carried out in the left hemisphere is going
12:09
Speaker 1: to manifest itself in the right. So if you're shaking
12:13
Speaker 1: somebody's hand using your right hand, the left hemisphere is
12:16
Speaker 1: is blowing up. That's right. If you're taking in um
12:20
Speaker 1: visual information with just your left eye because you got
12:22
Speaker 1: your right eye closed or it was poked out by
12:24
Speaker 1: a seagull or whatever, then your right hemisphere is going
12:28
Speaker 1: to be active, right, that's right. Interestingly, though, if the
12:32
Speaker 1: opposite isn't true, if you have your language center in
12:36
Speaker 1: your right hemisphere, it doesn't always mean that you're going
12:41
Speaker 1: to be left handed. It means you're more likely to.
12:44
Speaker 1: But um, I like the way this article looked at it.
12:46
Speaker 1: It's it's an evolutionary rule of thumb. It's not. I
12:49
Speaker 1: think they said between sixty one and se of lefties
12:53
Speaker 1: have the language centers on the left. Um over of
12:58
Speaker 1: right handed people, which raises a really great question, are
13:03
Speaker 1: is there such a thing as right eas and lefties
13:07
Speaker 1: or is there such a thing as right ees and
13:09
Speaker 1: non right ees? Because if there, if the if a
13:12
Speaker 1: righty and a lefty are equally exactly the same thing,
13:15
Speaker 1: if handedness is completely um binary like that, then if
13:19
Speaker 1: you're a lefty, your language center should be on the
13:22
Speaker 1: right hand side, and that, like you said, that's just
13:25
Speaker 1: not the case in most lefties even Yeah, that's true,
13:29
Speaker 1: and uh I O nine article also points out that
13:32
Speaker 1: it's they don't know why necessarily, but this is just
13:36
Speaker 1: how we evolved. It could have just been the opposite
13:39
Speaker 1: right and then we'd have more lefties, right, Yeah, well
13:41
Speaker 1: that's the idea. But I think, um, there are a
13:44
Speaker 1: couple of the explanations, possibly of genetic mutations along the
13:49
Speaker 1: way too, In particular, UH one about two hundred thousand
13:53
Speaker 1: years ago that basically mutated us to the fact that
13:58
Speaker 1: we are going to be more right handed in the
14:00
Speaker 1: in the language center is going to be on the
14:02
Speaker 1: left hand side. And then more recently, um, there's a
14:06
Speaker 1: theory that there was a second mutation uh between twenty
14:10
Speaker 1: thousand and a hundred thousand years ago where that basically
14:14
Speaker 1: balanced things out, or it canceled that out, which means
14:17
Speaker 1: the possibility of left handedness became a thing, or else
14:20
Speaker 1: we would have all been right handed. That makes sense too,
14:24
Speaker 1: It does make sense and that the humans possibly evolved
14:29
Speaker 1: to use their hands more, and by using their hands more,
14:32
Speaker 1: our brains were forced to become specialized and basically forced
14:36
Speaker 1: to choose. So then some sort of gene was set
14:39
Speaker 1: up that made the developing human brain most likely to
14:43
Speaker 1: be a right handed person. Right, And then that second
14:47
Speaker 1: gene came along and canceled that out in some parts
14:50
Speaker 1: of the population. I think it's the D gene and
14:53
Speaker 1: the C gene. Um there are two alleles, which is
14:58
Speaker 1: the manifestations of a gene at the same location, and
15:02
Speaker 1: the D gene is more frequent in the population, so
15:06
Speaker 1: it's more uh promotes the right handed preference. The C
15:09
Speaker 1: gene is less likely within the gene pool UH. And
15:12
Speaker 1: so there you have like a fifty fifty chance of
15:16
Speaker 1: being left handed if you have that C gene. Okay,
15:20
Speaker 1: I got you, Yeah, But you don't have a being
15:24
Speaker 1: a left handed person in general. You have about it
15:27
Speaker 1: only if you yeah, because the D gene is more prominent,
15:31
Speaker 1: and that means almost certainly you're going to be right handed. Okay,
15:34
Speaker 1: So the caveat we should add to all of this
15:36
Speaker 1: is that, um, this is all just strictly conjecture. UM.
15:40
Speaker 1: And we'll get to a little more of this conjecture
15:42
Speaker 1: right after this. So, Chuck, we're saying that it's possible
16:02
Speaker 1: that genetic mutations far back in human history account for this,
16:07
Speaker 1: and UM, there's a lot of evidence that there have
16:10
Speaker 1: humans have been mostly right handed for about the last
16:13
Speaker 1: two hundred thousand years. Fossil evidence suggests this. Looking at
16:17
Speaker 1: um Neanderthal skeletons, early human skeletons, UM, you can see
16:23
Speaker 1: evidence on the skeletons of right handedness, and they think
16:26
Speaker 1: that it's so obvious and obviously prominent because these people
16:31
Speaker 1: were using things like spears, So if they did have
16:34
Speaker 1: a hand preference, then a spear would definitely develop that
16:39
Speaker 1: arm connected to that hand, and it would stay in
16:42
Speaker 1: the fossil record through the skeletons. Right. They also have
16:46
Speaker 1: looked at other fossils as far back as one point
16:50
Speaker 1: six million years. There's a skeleton called, I want to say,
16:53
Speaker 1: the Kokomo Boy. Even though it's not, but I love
16:57
Speaker 1: that song. It's the Nario quote, my boy, you love Cocomo.
17:01
Speaker 1: Sure uh And he is at one point six million
17:05
Speaker 1: year old Homo air Gaster. And um, they he was
17:10
Speaker 1: clearly right handed as well. Other fossils have turned up
17:13
Speaker 1: evidence of right handedness them the teeth. Striations on the
17:17
Speaker 1: teeth suggest eating with their right hand. So what we
17:21
Speaker 1: what we can stay with a pretty decent amount of
17:23
Speaker 1: confidences that at least for the last two hundred thousand years,
17:26
Speaker 1: humanity has been a majority right handers, and there's been
17:31
Speaker 1: maybe about this constant ten proportion of left handed people,
17:37
Speaker 1: which makes the mystery even more crazy to me. Yeah,
17:40
Speaker 1: but it also makes sense that um an early tool
17:44
Speaker 1: building and teaching how to use tools, UM, I mean
17:48
Speaker 1: it holds true today. They've done studies that you know,
17:50
Speaker 1: you teach your son or daughter to tie a tie,
17:53
Speaker 1: and it's it's going to be more difficult if they're
17:55
Speaker 1: left handed and you're right handed for them to try
17:57
Speaker 1: and do it with their left hand, so or they'll
18:00
Speaker 1: pick it up easier if they go against their instinct
18:03
Speaker 1: and learn it how you've talked with. The studies have
18:06
Speaker 1: shown that so you learn faster from watching somebody and
18:09
Speaker 1: then using the same hands that they do. Yeah, and
18:13
Speaker 1: that makes sense. Back in the you know, with Took
18:15
Speaker 1: took in showing his pal how to use the bone
18:19
Speaker 1: to smash skull. You know, it's if he picks off
18:23
Speaker 1: his buddy picks up with his left hand, Took Took's
18:25
Speaker 1: gonna shake his head. No, no, yeah, use right hand
18:29
Speaker 1: or they're just gonna you know, they want. Everyone wants
18:31
Speaker 1: to fit in, even back at in the old days. Well,
18:34
Speaker 1: that's actually a suggestion of why left handedness is possibly
18:38
Speaker 1: not a little more prevalent among a certain age group
18:42
Speaker 1: today because it was equated with being weird or off
18:47
Speaker 1: or crazy or whatever. Um. And parents and teachers would
18:53
Speaker 1: force children to learn how to write with their right hand,
18:57
Speaker 1: effectively wiping out a lot of the left hand to population.
19:01
Speaker 1: Yeah and um, just jumping back a minute, I wanted
19:05
Speaker 1: to mention something important that the whole correlation versus causation thing,
19:10
Speaker 1: um with the whole language center link. Uh, it's not
19:14
Speaker 1: necessarily that that's a correlation. They appear to be strongly linked,
19:18
Speaker 1: but no one is saying that because the language hemisphere
19:22
Speaker 1: is on the left side of your brain that's causing
19:24
Speaker 1: you to be right handed right there there. And again,
19:26
Speaker 1: the reason that they are linked in a lot of
19:29
Speaker 1: scientists minds is that speech and fine motor skills are
19:35
Speaker 1: basically uniquely human, almost uniquely human. And it's just a
19:40
Speaker 1: little it's kind of like a red flag or a
19:42
Speaker 1: signal that they're both usually in the same hemisphere, and
19:46
Speaker 1: they do seem to be connected. And one hypothesis for
19:50
Speaker 1: why they're connected I thought was pretty smart. Um the
19:53
Speaker 1: idea that language spoken language emerged out of gestures hand movements,
20:00
Speaker 1: which we require fine motor skills, right, but I don't
20:03
Speaker 1: have trying to do the two legit to quit things.
20:06
Speaker 1: But the idea that language emerged out of that would
20:09
Speaker 1: suggest some sort of connection between the two, Like maybe
20:12
Speaker 1: the fine motor skill section is the more ancient of
20:15
Speaker 1: the two, and then language evolved out of that. But
20:18
Speaker 1: we also still need our fine motor skills to like
20:21
Speaker 1: eat with a fork and knife and everything, so it's
20:23
Speaker 1: stuck around. It didn't become obsolete just because we started speaking. Yeah,
20:27
Speaker 1: I like that theory. Um. We we did mention that
20:30
Speaker 1: this is a largely uniquely human trait um, But they
20:35
Speaker 1: have followed. Uh, they've basically been looking at our closest
20:38
Speaker 1: ancestors to try and figure a lot of this stuff out.
20:41
Speaker 1: Although it did see some studies that said that, like,
20:44
Speaker 1: cats are left handed because they'll go to swat things
20:47
Speaker 1: with their left hand. But um, I'm not so sure
20:49
Speaker 1: about that. Yeah, there's not only is it difficult apparently
20:53
Speaker 1: to um test or do you attribute handedness to an animal,
20:59
Speaker 1: it's also difficult to attribute handedness to a person because
21:02
Speaker 1: the idea of whether or not you're left handed or
21:05
Speaker 1: right handed, Um, it's still questionable. Like if you write
21:09
Speaker 1: with your right hand, but you actually can write better
21:13
Speaker 1: with your left hand or something like that. Right which
21:16
Speaker 1: what are you? Yeah, is the one you're comfortable with
21:19
Speaker 1: the one that you're actually better with? Yeah, that's a
21:21
Speaker 1: good point. Um. But they have been looking at our
21:25
Speaker 1: our primate ancestors since about the nineteen twenties, and they
21:29
Speaker 1: have found patterns. Um. Apparently lemurs and are more left handed,
21:34
Speaker 1: and other prosim uh persimians um, Macaques and old World
21:39
Speaker 1: monkeys for the most part are evenly split, and gorillas
21:43
Speaker 1: and chimpanzees are about thirty five lefty. Um, But this
21:47
Speaker 1: is interesting. The more, as they say here, the more primitive,
21:51
Speaker 1: the primate, the more likely it is to be a lefty,
21:55
Speaker 1: which goes in the opposite of the gene mutation. It's
22:02
Speaker 1: the exact opposite. It implies that we were originally left
22:06
Speaker 1: handed as primates, and then as we evolved, we became
22:09
Speaker 1: right handed. So therefore right handed people are more evolved
22:12
Speaker 1: than left handed people in some weird way. Yeah. So
22:15
Speaker 1: again it's another inconsistency where and of course this is
22:17
Speaker 1: in primates too. Um, that doesn't necessarily mean it's the
22:22
Speaker 1: same thing with humans. No, definitely not. But I mean,
22:26
Speaker 1: if you're looking at our ancestry and trying to figure
22:28
Speaker 1: out where handedness came from, you have to go pretty
22:31
Speaker 1: far back right, And I that's a pretty good example
22:35
Speaker 1: of how this body of work or knowledge is very contradictory. Still, yeah,
22:41
Speaker 1: it's baffling, it's pretty awesome. Hey, Chucky, you sent me
22:45
Speaker 1: something about um ambidextrous nous. Yeah, I thought this is
22:49
Speaker 1: kind of interesting from mental flaws like, like, it was
22:52
Speaker 1: just kind of my understanding that anybody who said, oh,
22:55
Speaker 1: I'm ambidextrous knew what they were talking about. But it
22:57
Speaker 1: turns out that's really just not the case. For the
23:00
Speaker 1: most part. It's a very rare um condition. I guess
23:04
Speaker 1: you'd call it yeah, UM, because I don't know if
23:08
Speaker 1: there is as a strict definition for what constitutes being ambidextrous.
23:14
Speaker 1: Like a you know, a switch hitter in baseball doesn't
23:18
Speaker 1: necessarily mean they're ambidextrous. It means they've taught themselves to
23:21
Speaker 1: hit from the other side of the plate. Um. If
23:25
Speaker 1: you notice, as a baseball fan, you're never gonna see
23:28
Speaker 1: a player that hits uh equally as well on both sides,
23:34
Speaker 1: Like you know, the great Chipper Jones here from Atlanta,
23:37
Speaker 1: he favored one side of the plate. Although he was
23:39
Speaker 1: a switch hitter, he was a much better hitter. I
23:41
Speaker 1: think it was as a lefty and not as a righty.
23:44
Speaker 1: So that's not a dextrous now, someone who's taught themselves
23:47
Speaker 1: because it's a valuable skill in sports to be somewhat
23:51
Speaker 1: embeddextrous or in a lot of sports. UM. But as far,
23:54
Speaker 1: I think writing is one of the things that they
23:56
Speaker 1: can look at um as a clear indicator of which
23:59
Speaker 1: hand uh you're you're best at, And they say about
24:03
Speaker 1: only about one percent can write equally as well with
24:06
Speaker 1: either hand. So that's like super low. Um. Apparently too
24:12
Speaker 1: So this handedness and this um lateralization of the brain
24:15
Speaker 1: and division of labor and all that has a lot
24:17
Speaker 1: to do with how your brain is connected. And apparently
24:19
Speaker 1: handedness is a part of that too. So like, for example, UM,
24:23
Speaker 1: people who are ambidextrous UM are more likely to suffer
24:27
Speaker 1: from schizophrenia, to have schizophrenia. And there it's not just
24:32
Speaker 1: UM ambidextrous people. Apparently lefties UM show a greater propensity
24:37
Speaker 1: towards schizophrenia. Something like people with schizophrenia are left handed,
24:43
Speaker 1: which is a very high proportion considering the general populations,
24:47
Speaker 1: about ten percent, and UM more than that, dyslexia and
24:50
Speaker 1: stuttering as well, right, which suggests that left handedness has
24:56
Speaker 1: an effect on how your brain is wired. It's not
25:00
Speaker 1: it's too simple, Oh my my hand is I use
25:03
Speaker 1: my left hand. My my brain is otherwise the exact
25:06
Speaker 1: same as a right handed person. The brain does appear
25:10
Speaker 1: to be different in some ways, especially in the ways
25:13
Speaker 1: that it's connected. Yeah, the um. We we talked about
25:16
Speaker 1: synesthesia before, one of our favorite Uh what do you
25:20
Speaker 1: call it? Not a condition? Is it? Yeah? Is it? Sure?
25:25
Speaker 1: I always just think of condition is something that's uh,
25:28
Speaker 1: you know, derogatory yeah, like a malady or something. I mean,
25:34
Speaker 1: I think that falls under that one is one, but
25:37
Speaker 1: the other one isn't necessarily that one. So like a
25:39
Speaker 1: malady is a condition, but excerption is necessarily malady. Anyway,
25:44
Speaker 1: that's my long windway of saying. Synist eats are awesome. Uh.
25:47
Speaker 1: And the rate of and uh ambidextran synistats is much
25:51
Speaker 1: higher uh and left handedness than in the general population. Right.
25:54
Speaker 1: So we have some clues here, like, UM, it's it's
25:59
Speaker 1: handedness has to do with how your brain is wired,
26:01
Speaker 1: and if your brain is wired in such a way
26:04
Speaker 1: that you are left handed, your brain is wired differently
26:07
Speaker 1: from a person with a right handed brain. Right, And
26:11
Speaker 1: a lot of studies have backed that up and have
26:13
Speaker 1: come up with things like it's entirely possible that if
26:17
Speaker 1: you're a left handed person you've got some advantages in life.
26:20
Speaker 1: We'll talk about those right after this. So, Chuck, one
26:40
Speaker 1: of the things that UM left handedness possibly bestows confers
26:45
Speaker 1: upon you as a benefit is the idea of thinking quicker,
26:49
Speaker 1: to be able to process information more quickly. Yeah. Uh,
26:53
Speaker 1: they have done some studies on this. UM did did
26:57
Speaker 1: a couple of studies. One of which they sat down
27:00
Speaker 1: on a hundred people, eighty right handers, twenty left handers,
27:03
Speaker 1: and basically to show them a computer screen with a
27:06
Speaker 1: single dot either on the left or the right side,
27:08
Speaker 1: and you had to press a button. It's just a
27:10
Speaker 1: speed test basically like which side is it on? Left
27:13
Speaker 1: or right? Right? So something shows up on the left side.
27:15
Speaker 1: I'm sure you have a clicker in your left hand
27:17
Speaker 1: and clicker in your right hand. You click the left
27:18
Speaker 1: hand clicker. But this is all happening very fast, that's right, UM,
27:22
Speaker 1: and left handed subjects were overall faster. Uh. And the
27:26
Speaker 1: other tests they had to match up multiple letters that
27:28
Speaker 1: appeared in some cases on either side of the line
27:31
Speaker 1: and in other cases on just one side. And again
27:34
Speaker 1: left handed, Uh, we're faster, but just at matching letters
27:38
Speaker 1: that were on both sides of the line, which I
27:41
Speaker 1: thought was interesting well, and that supports this idea that
27:44
Speaker 1: UM the the brain. The fact that UM, some left
27:49
Speaker 1: handed people's motor skills and language centers are on different
27:54
Speaker 1: sides in their brains, UH could make them talk more.
27:59
Speaker 1: The side of their hemispheres of their brains are more connected.
28:03
Speaker 1: There's more white tissue where their corpus colossum is more efficient.
28:06
Speaker 1: It makes sense in a way, but at the same
28:09
Speaker 1: time you're like, wait, that doesn't make any sense. So
28:12
Speaker 1: it's kind of this data should be taken and just
28:15
Speaker 1: locked away in a box until we understand the whole
28:18
Speaker 1: thing more, because it doesn't really do do a lot
28:21
Speaker 1: at this point, we don't know enough to make it fit.
28:24
Speaker 1: And it's actually kind of contradictory to some other stuff
28:27
Speaker 1: too as far as handedness goes. Yeah, but they do
28:30
Speaker 1: say that if you're left handed, you may be like
28:31
Speaker 1: a better gamer or or a pilot because you're able
28:36
Speaker 1: to just process this quick information super fast, like rapid
28:41
Speaker 1: fire stuff coming at you. It also suggested to that
28:44
Speaker 1: language can be processed in both hemispheres among left handed people,
28:48
Speaker 1: which again would require a lot more connections between the
28:52
Speaker 1: two hemispheres, faster communication between the two, and hence quicker thinking. Yeah,
28:58
Speaker 1: and that you in the long run, as you age
29:00
Speaker 1: and your brain deteriorates, you may be in better shape
29:03
Speaker 1: as a lefty because your other hemisphere may be able
29:07
Speaker 1: to pick up that slack more easily, whereas if you're
29:10
Speaker 1: just a dumb right hander, you're just you know, screwed.
29:14
Speaker 1: You're in and of course this has approven. This is
29:17
Speaker 1: just there postulating here, but I mean adds to this mystery. Yeah,
29:23
Speaker 1: you definitely haven't an advantage in sports in a lot
29:25
Speaker 1: of cases though. Yes, but not in the way that
29:29
Speaker 1: you would think. It's not necessarily because your brain is communicating.
29:33
Speaker 1: The hemispheres are of your brain are communicating. It's more
29:36
Speaker 1: because your opponent is statistically likelier to be expecting you
29:40
Speaker 1: to be a right handed person, to have trained against
29:43
Speaker 1: the right handed person exactly, to be used to playing
29:47
Speaker 1: a right handed person. Whereas if you're a left handed person,
29:50
Speaker 1: they're playing you now, you're gonna throw them off guard.
29:53
Speaker 1: You're gonna catch them off guard, you're gonna be able
29:55
Speaker 1: to get the drop on them because they're not used
29:57
Speaker 1: to you, Whereas you, being a lefty, you're still statistically
30:01
Speaker 1: likelier to have played right handed people, so you know
30:04
Speaker 1: how to handle them. They don't know how to handle you.
30:07
Speaker 1: You're the wild card, baby, You win your Rocky. Yeah,
30:11
Speaker 1: Rocky was left handed. Apparently, Um, and there's a bunch
30:14
Speaker 1: of sports figures in real life that we're left handed,
30:18
Speaker 1: and apparently it's one of those things where they're disproportionately
30:22
Speaker 1: represented as far as successful athletes go compared to the
30:26
Speaker 1: to the population at large. Yeah, and I think, um,
30:29
Speaker 1: a lot of times you'll hear about like m M
30:31
Speaker 1: A or boxing. Um. Tennis is another big one because
30:34
Speaker 1: if you're used to playing righties most of your life,
30:37
Speaker 1: that left handed server comes up there and it's it's different,
30:40
Speaker 1: it's weird, right, and the difference is so pronounced that like,
30:43
Speaker 1: if you are a pro tennis player or something like that,
30:46
Speaker 1: or pro boxer, you're gonna train against the lefty before
30:50
Speaker 1: a match against the lefty. Yeah, you know you're gonna
30:53
Speaker 1: do what you can to prepare yourself. Yeah. And I
30:55
Speaker 1: think Robert Lamb wrote this on how staff works are
30:58
Speaker 1: left handers quicker, um so all better at sports and um.
31:02
Speaker 1: He also points out that through history, uh, this probably
31:06
Speaker 1: comes from like soldier training mainly training and fighting and
31:10
Speaker 1: jousting and sword fighting and everything against other rights as well.
31:14
Speaker 1: So a lefty would have a left handed warrior might
31:17
Speaker 1: be more prone to be, you know, the great leader,
31:20
Speaker 1: like perhaps Alexander the Great right who was supposedly left handed.
31:24
Speaker 1: What's weird though, is if that had been the case,
31:27
Speaker 1: if humans have been left handed and right handed, the
31:31
Speaker 1: proportions have been roughly the same for the last two
31:33
Speaker 1: hundred thousand years. If you're a left handed combatant, wouldn't
31:37
Speaker 1: then the proportion of left handed people have grown over
31:41
Speaker 1: time because of natural selection, because you you have an
31:45
Speaker 1: advantage in battle or something like that. So therefore the
31:48
Speaker 1: population of right handed people would drop in relation to
31:51
Speaker 1: the population of exactly. That makes sense, and I remember,
31:54
Speaker 1: but that hasn't happened. Yeah, I remember our podcasts on
31:59
Speaker 1: castles like eighty years ago. Remember they built the staircases
32:05
Speaker 1: going on the right hand side. Do you remember how mine?
32:09
Speaker 1: You don't amendingly difficult that was for me to understand. No,
32:13
Speaker 1: did you have our time with Oh? Yeah, we had
32:15
Speaker 1: to re record it I think really twice because I
32:17
Speaker 1: kept getting it wrong. Yeah. We also got in trouble
32:20
Speaker 1: for for a cussword in that one too. That was
32:24
Speaker 1: a dark day years ago. Um. Yeah, but the Yeah,
32:28
Speaker 1: the the castle steps would wind up on the right
32:30
Speaker 1: side of the wall to give the advantage to the
32:33
Speaker 1: person higher on the stairs swinging a right handed sword,
32:37
Speaker 1: because obviously you couldn't swing a right handed sword going
32:39
Speaker 1: up the stairs because the wall is on your right,
32:42
Speaker 1: But a left handed combatant advantage taken away even though
32:48
Speaker 1: you have the higher ground, because all of a sudden
32:51
Speaker 1: you're cutting the guy's knees off, were cutting them off
32:54
Speaker 1: at the knees. You know that hurts. It does. But
32:59
Speaker 1: also include with natural selection. Two is if there were
33:01
Speaker 1: any real disadvantages to being a left handed person, or
33:06
Speaker 1: there were advantages to being a right handed person, this
33:09
Speaker 1: population shouldn't have remained steady over that long of a
33:12
Speaker 1: period too. I see what you mean. You know, unless
33:15
Speaker 1: the advantage isn't so great as to you know, cause uh,
33:20
Speaker 1: that natural selection to occur. You know, maybe, Um, there
33:24
Speaker 1: are more US presidents that have been left handed, more
33:28
Speaker 1: MENSU members for whatever that's worth. Half half of the
33:31
Speaker 1: twelve US presidents so it's World War two have been
33:34
Speaker 1: left handed. So whereas the normal populations ten to fifteen
33:37
Speaker 1: percent lefties US presidents of World War two has been
33:42
Speaker 1: And apparently in campaign all three candidates H. W. Bush, Clinton,
33:49
Speaker 1: and Pero were left handed. Yeah, that's of the population.
33:54
Speaker 1: Peroh Man, he was fun to watch, he was Dana
33:58
Speaker 1: Carvey was fun to watch doing per to Yeah. Uh.
34:01
Speaker 1: And they say more musicians more or musicians are more
34:05
Speaker 1: likely to be left handed maybe. Um, and it does
34:08
Speaker 1: run in families, even though identical twins can have opposite
34:12
Speaker 1: hand preferences. Oh weird and um there is. In the
34:16
Speaker 1: nineteen eighties, it was a Harvard neurologist that said that, ah,
34:21
Speaker 1: lefties are right eas whose brain centers in the womb
34:25
Speaker 1: change because of high testosterone. Yeah, so there's there's theories
34:30
Speaker 1: that we become handed in the womb because of something
34:33
Speaker 1: like that, or birth trauma or some sort of trauma.
34:36
Speaker 1: While and that. Yeah, it just adjusts the the the
34:41
Speaker 1: construction of our brains. Um. Supposedly, a mother's age has
34:46
Speaker 1: an impact on her kids. That's crazy. Statistically, speaking of
34:51
Speaker 1: a mother, UM over forty who gives birth is has
34:56
Speaker 1: a higher likelihood of having a lefty kid, way higher,
34:58
Speaker 1: like hundred cent or something. Yeah, like that's pretty high.
35:02
Speaker 1: It's more, I don't even know what that means. Yeah,
35:06
Speaker 1: and then I guess your hand preference emerges about by
35:10
Speaker 1: seven months, but then it's like set by age three,
35:14
Speaker 1: So before seven months, you're just flinging poop with both
35:16
Speaker 1: hands equally as well. Pretty much. I wrote a story
35:20
Speaker 1: about a guy who found out as an adult that
35:22
Speaker 1: his mother had suspected he was left handed when he
35:25
Speaker 1: was a baby, so she immobilized his left hand so
35:30
Speaker 1: that he would be forced to learn with his right hand.
35:34
Speaker 1: He didn't seem to take it like that, but he did.
35:37
Speaker 1: It came across like he felt like something had been
35:39
Speaker 1: kind of taken from him. He said. It also explained
35:41
Speaker 1: a lot that he was like so so with stuff
35:44
Speaker 1: that involved its right hand seemed to be better with
35:47
Speaker 1: his left. And um that he looked into it, and
35:50
Speaker 1: that by doing that, which was very popular like kids
35:53
Speaker 1: were forced to become right handed through the twentieth century.
35:57
Speaker 1: Um that you are basically making a a less pronounced
36:05
Speaker 1: copy of the person. You're taking the original and making
36:09
Speaker 1: like a slightly dimmer effect simile of it, like forcing
36:13
Speaker 1: their baying to reorganize like that interesting, whereas they thought
36:17
Speaker 1: they were trying to give them an advantage, to actually
36:19
Speaker 1: give them a disadvantage exactly. But I would imagine that
36:22
Speaker 1: if you did that till say age eighteen, and then
36:27
Speaker 1: all of a sudden started using your dominant hand that
36:29
Speaker 1: you were naturally born with. It's all like spin ley
36:32
Speaker 1: in week right. But then once you once you train
36:34
Speaker 1: it to to to bulk back up, I would imagine
36:38
Speaker 1: your brain would would be better off like that and
36:41
Speaker 1: be fuller. So to continue the abuse right until eighteen
36:45
Speaker 1: dis continued the abuse and then bam, you got a
36:48
Speaker 1: super kid on your take your little old man Spinley,
36:51
Speaker 1: hands and fingers like build them back up? And Mr
36:54
Speaker 1: Show character remember Titanico and they were crossing the hospital.
37:01
Speaker 1: You know they're getting back together. Yeah, yeah, that's exciting.
37:04
Speaker 1: So p FT tweeted something some picture is very excited
37:08
Speaker 1: the whole gang. If you want to know more about
37:11
Speaker 1: Paul if Tompkins or Handedness or Mr Show or any
37:14
Speaker 1: of that jazz, you can type that stuff into the
37:16
Speaker 1: search bar at how stuff works dot com. Since I
37:19
Speaker 1: said search, part's time for a listener mail. I'm gonna
37:25
Speaker 1: call this Christian shout out. Hey, guys started listening to
37:28
Speaker 1: a few months ago, and I've already listened to about
37:31
Speaker 1: a hundred and sixty episodes. Um and by the way,
37:35
Speaker 1: we've mentioned this a lot, but if you're just on iTunes,
37:38
Speaker 1: say and you think, boy, these guys have got three
37:39
Speaker 1: hundred episodes three one, Yeah, we've got like how many
37:44
Speaker 1: now seven change yea seven hundred plus that you can
37:48
Speaker 1: find on our website. Um. Stuff, you should know dot Com. Yeah,
37:51
Speaker 1: and as a little pro tip, if you go onto
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Speaker 1: stuff you should know dot com a k the website
37:56
Speaker 1: with one of the worst searches in the world. Just
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Speaker 1: do control F and open up your web browsers search
38:03
Speaker 1: and then type it in and on our podcast archive page.
38:06
Speaker 1: If you're looking for something, yes, okay, they'll bring it up.
38:08
Speaker 1: Don't search for it. Don't bother searching for it using
38:10
Speaker 1: our search tool. Are we working on that? I hope so,
38:15
Speaker 1: because this is really bad, like it doesn't bring up
38:18
Speaker 1: anything really yeah, wow, that's pretty bad. Otherwise it even there,
38:23
Speaker 1: I don't know. I guess for looks lane. Um. So,
38:28
Speaker 1: getting back to this, we do have a lot of
38:29
Speaker 1: podcasts out there, for those of you who don't know,
38:31
Speaker 1: we have seven hundred plus we're talking about. He's uh,
38:35
Speaker 1: he listened to a hundred and sixty episodes. His favorite
38:38
Speaker 1: thing about them is how you don't poop poo anybody's beliefs.
38:42
Speaker 1: I'm a Christian, So when I was very much so
38:44
Speaker 1: begrudgingly uh listen to your evolution suite. I was expecting
38:49
Speaker 1: to be mad, but to my surprise, I heard a
38:52
Speaker 1: very non bias view of evolution. Um I do believe
38:54
Speaker 1: in evolution, but it's a long story. By the way,
38:56
Speaker 1: after many years of hearing creation a slam uh people
39:00
Speaker 1: talk about evolution is a very pleasant surprise. So I
39:03
Speaker 1: just want to say thanks for putting your hearts but
39:05
Speaker 1: not your opinions into that episode. That is from Matt
39:08
Speaker 1: very sincerely, and uh, we've been taking a task here
39:11
Speaker 1: and there. We try to do our best, matt um,
39:14
Speaker 1: to keep things on the level like that, but we
39:17
Speaker 1: are human and we do uh flounder here and there
39:20
Speaker 1: with that, but we we try, and we appreciate your
39:23
Speaker 1: kudos for that. Yeah, thanks man. Yeah, if you want
39:26
Speaker 1: to give us kudos, we would love to hear about that.
39:29
Speaker 1: Or if you have any great stories that has to
39:31
Speaker 1: do with handedness, let us know if you had your
39:33
Speaker 1: arm tied to your waist till you're eight as a baby. Yeah. Uh.
39:37
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39:41
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