WEBVTT - Why Do Lefties Exist? 0:00:01.120 --> 0:00:04.560 Welcome to Stuff you Should Know from House Stuff Works 0:00:04.600 --> 0:00:13.080 dot com. Hey, I'm welcome to the podcast. I'm Josh 0:00:13.119 --> 0:00:17.079 Clark with Charles W Chuck Bryant and Jerry's over there too, 0:00:18.079 --> 0:00:22.120 and this is stuff you should know the podcast. Man, 0:00:22.200 --> 0:00:26.320 oh man, I would love for people to just lie 0:00:26.360 --> 0:00:31.520 on the wall in the studio. Sometimes get squashed. There's 0:00:31.560 --> 0:00:34.000 a lot of fun prerecord today. People. I hate that 0:00:34.040 --> 0:00:35.960 you miss out on that kind of stuff. But you 0:00:35.960 --> 0:00:38.680 know what, that's a that's for us. We we deserve 0:00:38.720 --> 0:00:43.960 a little something. Yeah, and that's called pre show fun, fun, 0:00:44.840 --> 0:00:49.200 hammering out the details, hammering other details. I thoroughly enjoyed 0:00:49.200 --> 0:00:52.159 researching this one. Oh really, it burned my brain a 0:00:52.200 --> 0:00:53.920 little bit. It burned my brain a little bit too, 0:00:53.920 --> 0:00:57.760 But um, I just I didn't know anything about handedness 0:00:58.520 --> 0:01:01.800 and uh no not don't use your hands much. Well, 0:01:01.840 --> 0:01:04.280 I mean as far as, uh why you are left 0:01:04.360 --> 0:01:06.560 or right handed or ambidextrous. It was all kind of 0:01:06.600 --> 0:01:09.720 new information for me. I feel like I had read 0:01:09.760 --> 0:01:12.440 that Io nine article, which we should give a huge 0:01:12.440 --> 0:01:15.360 shout out because it was forming partially the basis of 0:01:15.440 --> 0:01:19.200 this UM episode. Yeah, why are so few people left handed? 0:01:19.240 --> 0:01:22.479 From Io nine and they sourced a lot of great 0:01:22.480 --> 0:01:25.920 stuff from Discover magazine and their articles, so and science 0:01:26.120 --> 0:01:30.360 and science, so it's legit. It is legit. Uh, possibly 0:01:30.400 --> 0:01:34.960 even to legit to quit yeah, yeah, which I could 0:01:35.000 --> 0:01:37.120 not do with my left hand. I guess I can't. 0:01:37.120 --> 0:01:40.480 I just did it. You just did to your science 0:01:40.480 --> 0:01:46.080 sign signing to me. I'm equally bad at at doing 0:01:46.080 --> 0:01:49.040 too legit to quit finger motions with either hand. I'm 0:01:49.160 --> 0:01:52.480 right handed, by the way, what about you, I'm right handed, 0:01:52.480 --> 0:01:54.600 but that is weird since you have your mc hammer 0:01:54.600 --> 0:01:56.240 pants on. I thought you would be good at that. 0:01:56.240 --> 0:01:58.919 That's all just it's not hard to put on pants. 0:01:59.000 --> 0:02:01.920 It's hard to do too legit a quit finger motions. Yeah, 0:02:01.920 --> 0:02:04.840 I'm right handed. Um to well, I was about to say, 0:02:04.840 --> 0:02:08.200 to a fault, but heavily heavily right handed, because after 0:02:08.240 --> 0:02:10.600 reading this, I do believe that there is a bit 0:02:10.600 --> 0:02:15.200 of a spectrum. I think, um oh yeah, yeah. I think. 0:02:15.400 --> 0:02:18.639 I think some people are way dominant with their one hand, 0:02:18.639 --> 0:02:20.920 and some people skew more towards you. I can do 0:02:20.960 --> 0:02:24.280 some things with this hand, uh, And some people are ambidexterous, 0:02:24.280 --> 0:02:27.440 which we'll talk about. Very few, though fewer than you. Think, yeah, 0:02:27.600 --> 0:02:30.960 But um, I am heavily, heavily right handed. I cannot 0:02:30.960 --> 0:02:38.200 do many uh what's the word I'm looking for? Um? Fine, 0:02:38.960 --> 0:02:41.880 not like my fine motor skill tasks. I cannot do 0:02:42.000 --> 0:02:44.040 very well with my left hand. I can just like 0:02:44.120 --> 0:02:47.359 club things and smack things and knock stuff over, knock 0:02:47.400 --> 0:02:51.680 stuff over like Frankenstein clearing a table pretty much. What 0:02:51.760 --> 0:02:53.720 about you? And can you do anything with your left hand? 0:02:54.040 --> 0:02:57.560 I used to think I was, you know, pretty much 0:02:57.600 --> 0:03:01.000 just strictly right handed, But then i've it's especially researching this, 0:03:01.080 --> 0:03:03.639 I paid attention, and I'm like, no, I used my 0:03:03.639 --> 0:03:05.560 my left hand a little more than I thought. I'm 0:03:05.560 --> 0:03:08.040 definitely not ambidextrous. And if there is such a thing 0:03:08.040 --> 0:03:10.480 as a dominant hand, it's clearly my right. But this 0:03:10.639 --> 0:03:13.600 this article points out, or actually it was a science 0:03:14.160 --> 0:03:18.639 m article that said, there's there's this idea that there 0:03:18.720 --> 0:03:22.360 isn't a dominant hand, that you have uses for both hands, 0:03:22.400 --> 0:03:24.480 and one kind of specializes in one thing and one 0:03:24.520 --> 0:03:27.480 specializes in another. And the the example they used to 0:03:27.480 --> 0:03:31.040 illustrate that was, um, cutting like meat with a fork 0:03:31.040 --> 0:03:33.000 and knife. Yeah, I was gonna ask you about that, 0:03:33.080 --> 0:03:35.920 you know, Like I was thinking about I was like, oh, yeah, 0:03:35.960 --> 0:03:37.400 I guess I do use the knife pretty well with 0:03:37.400 --> 0:03:40.520 my left hand. I thought, crazy, No, my fork is 0:03:40.520 --> 0:03:43.480 in my left hand, my knife is in my right hand. 0:03:44.160 --> 0:03:46.680 And then I switched the fork over to my right hand. 0:03:46.720 --> 0:03:48.240 That's what I did too. I was gonna ask you that. 0:03:48.360 --> 0:03:51.000 So I'm definitely right handed, but you know my left 0:03:51.000 --> 0:03:54.160 hand does a great job holding the steak in place 0:03:54.200 --> 0:03:56.840 with my fork while I cut it with the knife. Yeah. Well, 0:03:56.880 --> 0:03:58.440 I'll come to think of it, though, I play guitar 0:03:58.800 --> 0:04:01.720 in drums, so I mean I have some left hand skill, 0:04:01.760 --> 0:04:04.400 I guess. Um. And I know if you break your 0:04:04.440 --> 0:04:08.360 dominant hand, you're gonna learn pretty quickly how to adapt. 0:04:09.160 --> 0:04:12.920 So it's possible to learn, uh, if forts to. It's 0:04:12.960 --> 0:04:15.200 all very interesting to me. It is, and we should say, 0:04:15.240 --> 0:04:18.480 if you happen happen just randomly to be listening to 0:04:18.520 --> 0:04:24.000 this episode on August thirteen, Happy National Left Handed Day, 0:04:25.120 --> 0:04:26.600 I looked out. When I looked that up, I was like, 0:04:26.640 --> 0:04:28.560 I wouldn't it be one of those another stuff you 0:04:28.560 --> 0:04:32.320 should know coincidence If this was happened to be released, No, 0:04:32.640 --> 0:04:36.640 not even close. Um. And it's good that left handed 0:04:36.640 --> 0:04:39.200 people have their own day because they've been fairly maligned 0:04:39.200 --> 0:04:43.880 throughout the millennia. Yeah, let's talk about that. Actually, okay, 0:04:44.440 --> 0:04:47.880 Um throughout history. In fact, even if you look at 0:04:47.920 --> 0:04:52.359 the words uh throughout history, there is a you know, 0:04:52.760 --> 0:04:56.360 uh the poopoo left handers. Basically like the word l 0:04:56.560 --> 0:05:00.680 y f T left yeah from Anglo Saxon means weak 0:05:01.360 --> 0:05:03.919 and the words where the word left comes from and 0:05:03.960 --> 0:05:07.120 the word sinister from Latin is the word for left. Yeah. 0:05:07.160 --> 0:05:09.719 Anybody who saw that episode of The Simpsons where Ned 0:05:09.720 --> 0:05:13.760 Flanders opens the left Toorium knows that because because I 0:05:13.839 --> 0:05:18.160 have a sinister reason to invite you all here sinister 0:05:18.279 --> 0:05:21.160 meaning left handed man. And that was when he announced 0:05:21.160 --> 0:05:24.159 the Leftorium. That show was so smart, you know, very smart. 0:05:24.240 --> 0:05:26.520 So many of those jokes like just flew over my 0:05:26.560 --> 0:05:31.760 head back in the day, Well, they're coming back to roost. Uh. 0:05:31.800 --> 0:05:36.160 There's a long list of um countries who have languages 0:05:36.360 --> 0:05:40.359 that link the word right with being good uh and 0:05:40.360 --> 0:05:44.080 the left with being bad or wrong uh. And in 0:05:44.200 --> 0:05:47.640 some countries even making hand gestures with your left hand 0:05:47.680 --> 0:05:50.760 is a no no. Well, and a lot of countries 0:05:51.080 --> 0:05:53.640 are a lot of cultures that eat food with their hands. 0:05:54.120 --> 0:05:57.960 Then utensils. Um. Using the left hand to eat or 0:05:58.000 --> 0:06:00.800 do a lot of things with is considered taboo because 0:06:00.880 --> 0:06:03.000 the right it's exactly right. You use the right hand 0:06:03.040 --> 0:06:05.200 to eat with, use your left hand to wipe with 0:06:05.320 --> 0:06:09.080 right and um, I think if you pay attention and notice, 0:06:09.200 --> 0:06:12.359 I'll bet you have a hand that's dominant and that 0:06:13.000 --> 0:06:16.640 that um activity wipe in your butt. Yeah, yeah, I'm 0:06:16.640 --> 0:06:20.760 alrighty are you? Yeah? Okay? But if you if you 0:06:20.800 --> 0:06:23.920 try the other hand, it will feel very weird. Whatever 0:06:24.200 --> 0:06:27.080 whatever hand you use normally, it's gonna feel weird if 0:06:27.120 --> 0:06:30.040 you use the option, and you'll just send it very messy. Sure. 0:06:31.000 --> 0:06:33.280 I wonder if you had a subconscious thing like you know, 0:06:33.360 --> 0:06:35.800 I was just eating these candy pecons with my right hand, 0:06:36.080 --> 0:06:37.800 and I know I'm gonna go back and eat them 0:06:37.839 --> 0:06:39.839 with my right hand. Oh, I don't even use my 0:06:39.880 --> 0:06:42.240 hands to eat them. I'm a little too germ conscious. 0:06:42.279 --> 0:06:45.000 I scoop food up in the crook of my elbow, 0:06:45.520 --> 0:06:48.159 which is very clean because it doesn't come in contact 0:06:48.160 --> 0:06:49.800 of other stuff, and then I eat out of the 0:06:49.800 --> 0:06:54.560 crook of my elbow. That's pretty funny. Um. So why 0:06:54.800 --> 0:06:57.560 have people been I mean, why have they picked on 0:06:57.640 --> 0:07:00.200 left handed people. There are some theories that is just 0:07:00.560 --> 0:07:04.440 a minority. You know, ten of people are left handed, 0:07:04.480 --> 0:07:07.400 and throughout history minorities have been picked on. That's right, 0:07:07.440 --> 0:07:10.160 this one thing, Um, there's there's at least a couple 0:07:10.200 --> 0:07:14.400 of cultures that equate left handedness with clumsiness. Yeah, that 0:07:14.400 --> 0:07:20.240 makes sense to me. Some hypotheses theorized that UM tools 0:07:20.800 --> 0:07:24.200 tool making for a very long time, UM has been 0:07:24.240 --> 0:07:28.920 done following right handed techniques. Still is in many cases, sure, um. 0:07:29.040 --> 0:07:32.080 And so when a lefty was trying to make tools 0:07:32.160 --> 0:07:35.240 or do whatever using right handed tools, they would have 0:07:35.280 --> 0:07:39.040 been clumsy with them. And therefore the idea that left 0:07:39.080 --> 0:07:42.600 handed people were clumsy or weak or whatever could have 0:07:42.680 --> 0:07:46.840 developed and carried on. Yeah, like, uh, colonial day, dad 0:07:46.960 --> 0:07:49.840 is teaching his two sons. Let's go with the son 0:07:49.880 --> 0:07:52.880 and a daughter. Even, let's how to use a saw. 0:07:53.480 --> 0:07:55.320 And you know, the son's left handed and he keeps 0:07:55.440 --> 0:07:58.560 he can't saw well, so the dad's just like he 0:07:58.600 --> 0:08:01.160 favors the daughter because she's you know, she's better with 0:08:01.200 --> 0:08:03.320 the saw. It's just it's easy to see how that 0:08:03.320 --> 0:08:05.920 could happen. Like he's mad at Roger but pleased with 0:08:05.960 --> 0:08:10.000 Prudence because prudence. She's always sawing things. Well, that's a 0:08:10.040 --> 0:08:14.640 colonium name, right, Yeah, sure, well I feel like it is. Okay, 0:08:14.640 --> 0:08:19.360 well what else is there? Who? Goody? Uh, goody, Alice. Okay, 0:08:20.400 --> 0:08:25.600 it's timeless. Um, but there's still that if you're lefty today, 0:08:25.640 --> 0:08:27.800 you might be frustrated with things like scissors and can 0:08:27.840 --> 0:08:31.520 openers and spiral notebooks and things that sort of U 0:08:32.160 --> 0:08:34.920 favor the right handed. Yeah, we're sitting next to a 0:08:35.080 --> 0:08:38.720 right handed person at dinner. The elbow thing, it's the worst. 0:08:38.960 --> 0:08:42.000 It's because there's so few left handed people. If you're 0:08:42.040 --> 0:08:44.760 planning a dinner party, first of all, it's just common 0:08:44.800 --> 0:08:47.520 courtesy to know the handedness of all of your guests, 0:08:48.120 --> 0:08:50.760 and then to put the appropriately right to put the 0:08:50.840 --> 0:08:52.880 left handed person at the end of the table so 0:08:52.920 --> 0:08:55.959 that their left hand is their left elbow is off 0:08:56.000 --> 0:08:57.840 the table and they don't have to worry about bumping 0:08:57.840 --> 0:09:00.400 into other people. Yeah, my mom is left ended, my 0:09:00.480 --> 0:09:05.600 father is right handed, and you came out right handed. Yeah, crazy, 0:09:06.679 --> 0:09:11.920 I sure did so. Um. Despite everybody knowing that there's 0:09:11.920 --> 0:09:15.120 a right handedness and a left handedness, it turns out, 0:09:15.160 --> 0:09:20.439 after investigating this kind of thing, science is really baffled 0:09:20.440 --> 0:09:22.720 as to what exactly is going on, why we would 0:09:22.760 --> 0:09:26.839 have handedness, yeah at all, where it comes from. Why 0:09:26.880 --> 0:09:30.680 the proportions seem to be steady. There's a lot of 0:09:30.760 --> 0:09:35.280 questions that you know, come up when you look into handedness. 0:09:35.320 --> 0:09:37.400 Whereas you know the average person who just kind of 0:09:37.400 --> 0:09:41.400 take it for granted, but no, not the average scientists. No, no, no. 0:09:41.880 --> 0:09:45.480 There are a lot of interesting theories though. UM. One 0:09:45.600 --> 0:09:48.800 is is that, uh, as we all know, we have 0:09:48.840 --> 0:09:51.079 a left hemisphere in the right hemisphere of our brain, 0:09:51.760 --> 0:09:54.360 and we are one of the only mammals that are 0:09:54.480 --> 0:09:59.440 very much UM have a it's called brain lateralization when primarily, 0:09:59.480 --> 0:10:01.400 and this isn't a cross the board, but primarily one 0:10:01.440 --> 0:10:04.120 hemisphere controls certain things and the other controls other things. 0:10:04.679 --> 0:10:07.240 And that is primarily controlling the opposite side of the 0:10:07.280 --> 0:10:14.640 body as the hemisphere. UM. But language and um controlling 0:10:14.679 --> 0:10:16.920 your you know, fine motor skills like things you do 0:10:16.960 --> 0:10:20.080 with your hands and your fingers. I have often been 0:10:20.320 --> 0:10:25.240 linked because uh, they are generally on linked together and 0:10:25.360 --> 0:10:28.400 on one hemisphere of the brain right for for the 0:10:28.400 --> 0:10:30.400 most part, people who are right handed. They make up 0:10:30.440 --> 0:10:34.200 the vast majority of human beings by the way. Yeah, 0:10:34.200 --> 0:10:36.520 I saw as low as seventy, but nothing lower than that, 0:10:36.720 --> 0:10:41.520 you know, eighty didn't Yeah, you're right, sorry, exactly. Um, 0:10:43.080 --> 0:10:46.679 those people have their language center in the left hemisphere, 0:10:46.840 --> 0:10:50.199 and I guess also their motor cortex in the left hemisphere, 0:10:50.880 --> 0:10:56.280 and the know the left and the U. There's a 0:10:56.280 --> 0:10:58.200 lot of questions about why this would be when the 0:10:58.240 --> 0:11:01.960 brain supposedly is a is always looking for efficiencies as 0:11:02.000 --> 0:11:05.199 much as possible. So they're saying, okay, well, these are 0:11:05.240 --> 0:11:11.319 two very human activities speech language and using your fingers 0:11:11.360 --> 0:11:15.240 to do stuff, right, So, um, they're also some of 0:11:15.240 --> 0:11:18.520 the more complex activities that humans engage in. So it 0:11:18.600 --> 0:11:20.360 makes sense that you just leave it up to one 0:11:20.400 --> 0:11:23.679 side of the brain so that these things can um 0:11:24.480 --> 0:11:27.360 not have to cross over the corpus colossum. Yeah, it's 0:11:27.360 --> 0:11:29.719 it's just a cluster together. It makes sense. It does 0:11:29.800 --> 0:11:33.120 make sense, but it's also a pretty thin explanation. If 0:11:33.160 --> 0:11:36.040 you you could also say the other the exact opposite, 0:11:36.080 --> 0:11:38.840 that it would make more sense that our motor skills 0:11:38.960 --> 0:11:41.040 and our language skills would be in opposite sides of 0:11:41.040 --> 0:11:43.800 the brain to give each other a break, rather than 0:11:43.840 --> 0:11:47.120 just weighting it down on the same side. The point is, though, 0:11:47.160 --> 0:11:50.480 as if you crack open a human brain and you 0:11:50.600 --> 0:11:54.240 look for the motor cortex and the language region, the 0:11:54.320 --> 0:11:58.480 language center, you're gonna find them most likely, statistically speaking, 0:11:58.760 --> 0:12:03.280 on the left hemisphere. Hence more right handedness. Right because 0:12:03.280 --> 0:12:06.520 of what you said that um that brain literalization where 0:12:06.720 --> 0:12:09.760 stuff that's carried out in the left hemisphere is going 0:12:09.800 --> 0:12:13.360 to manifest itself in the right. So if you're shaking 0:12:13.400 --> 0:12:16.400 somebody's hand using your right hand, the left hemisphere is 0:12:16.400 --> 0:12:20.120 is blowing up. That's right. If you're taking in um 0:12:20.400 --> 0:12:22.839 visual information with just your left eye because you got 0:12:22.840 --> 0:12:24.760 your right eye closed or it was poked out by 0:12:24.760 --> 0:12:27.959 a seagull or whatever, then your right hemisphere is going 0:12:28.000 --> 0:12:32.560 to be active, right, that's right. Interestingly, though, if the 0:12:32.600 --> 0:12:36.120 opposite isn't true, if you have your language center in 0:12:36.320 --> 0:12:41.120 your right hemisphere, it doesn't always mean that you're going 0:12:41.120 --> 0:12:43.560 to be left handed. It means you're more likely to. 0:12:44.200 --> 0:12:46.400 But um, I like the way this article looked at it. 0:12:46.400 --> 0:12:49.080 It's it's an evolutionary rule of thumb. It's not. I 0:12:49.080 --> 0:12:53.160 think they said between sixty one and se of lefties 0:12:53.200 --> 0:12:58.600 have the language centers on the left. Um over of 0:12:58.880 --> 0:13:03.040 right handed people, which raises a really great question, are 0:13:03.280 --> 0:13:06.719 is there such a thing as right eas and lefties 0:13:07.200 --> 0:13:09.120 or is there such a thing as right ees and 0:13:09.240 --> 0:13:12.520 non right ees? Because if there, if the if a 0:13:12.640 --> 0:13:15.199 righty and a lefty are equally exactly the same thing, 0:13:15.320 --> 0:13:19.880 if handedness is completely um binary like that, then if 0:13:19.920 --> 0:13:22.800 you're a lefty, your language center should be on the 0:13:22.920 --> 0:13:24.880 right hand side, and that, like you said, that's just 0:13:25.000 --> 0:13:29.040 not the case in most lefties even Yeah, that's true, 0:13:29.480 --> 0:13:32.360 and uh I O nine article also points out that 0:13:32.480 --> 0:13:36.360 it's they don't know why necessarily, but this is just 0:13:36.520 --> 0:13:38.959 how we evolved. It could have just been the opposite 0:13:39.200 --> 0:13:41.520 right and then we'd have more lefties, right, Yeah, well 0:13:41.520 --> 0:13:44.920 that's the idea. But I think, um, there are a 0:13:44.920 --> 0:13:49.280 couple of the explanations, possibly of genetic mutations along the 0:13:49.320 --> 0:13:53.160 way too, In particular, UH one about two hundred thousand 0:13:53.240 --> 0:13:58.079 years ago that basically mutated us to the fact that 0:13:58.679 --> 0:14:00.760 we are going to be more right handed in the 0:14:00.840 --> 0:14:02.120 in the language center is going to be on the 0:14:02.200 --> 0:14:06.199 left hand side. And then more recently, um, there's a 0:14:06.280 --> 0:14:10.560 theory that there was a second mutation uh between twenty 0:14:10.600 --> 0:14:14.400 thousand and a hundred thousand years ago where that basically 0:14:14.440 --> 0:14:17.280 balanced things out, or it canceled that out, which means 0:14:17.320 --> 0:14:20.720 the possibility of left handedness became a thing, or else 0:14:20.760 --> 0:14:24.240 we would have all been right handed. That makes sense too, 0:14:24.480 --> 0:14:28.400 It does make sense and that the humans possibly evolved 0:14:29.400 --> 0:14:32.240 to use their hands more, and by using their hands more, 0:14:32.600 --> 0:14:36.240 our brains were forced to become specialized and basically forced 0:14:36.280 --> 0:14:38.960 to choose. So then some sort of gene was set 0:14:39.040 --> 0:14:43.160 up that made the developing human brain most likely to 0:14:43.200 --> 0:14:47.160 be a right handed person. Right, And then that second 0:14:47.320 --> 0:14:50.080 gene came along and canceled that out in some parts 0:14:50.120 --> 0:14:53.400 of the population. I think it's the D gene and 0:14:53.400 --> 0:14:58.440 the C gene. Um there are two alleles, which is 0:14:58.480 --> 0:15:02.160 the manifestations of a gene at the same location, and 0:15:02.720 --> 0:15:06.440 the D gene is more frequent in the population, so 0:15:06.520 --> 0:15:09.560 it's more uh promotes the right handed preference. The C 0:15:09.720 --> 0:15:12.760 gene is less likely within the gene pool UH. And 0:15:12.880 --> 0:15:16.040 so there you have like a fifty fifty chance of 0:15:16.120 --> 0:15:19.920 being left handed if you have that C gene. Okay, 0:15:20.160 --> 0:15:23.680 I got you, Yeah, But you don't have a being 0:15:24.440 --> 0:15:26.960 a left handed person in general. You have about it 0:15:27.200 --> 0:15:30.760 only if you yeah, because the D gene is more prominent, 0:15:31.080 --> 0:15:34.000 and that means almost certainly you're going to be right handed. Okay, 0:15:34.040 --> 0:15:36.160 So the caveat we should add to all of this 0:15:36.240 --> 0:15:40.360 is that, um, this is all just strictly conjecture. UM. 0:15:40.440 --> 0:15:42.320 And we'll get to a little more of this conjecture 0:15:42.520 --> 0:16:02.360 right after this. So, Chuck, we're saying that it's possible 0:16:02.360 --> 0:16:06.640 that genetic mutations far back in human history account for this, 0:16:07.360 --> 0:16:10.320 and UM, there's a lot of evidence that there have 0:16:10.920 --> 0:16:13.800 humans have been mostly right handed for about the last 0:16:13.840 --> 0:16:17.480 two hundred thousand years. Fossil evidence suggests this. Looking at 0:16:17.800 --> 0:16:23.160 um Neanderthal skeletons, early human skeletons, UM, you can see 0:16:23.200 --> 0:16:26.320 evidence on the skeletons of right handedness, and they think 0:16:26.360 --> 0:16:30.960 that it's so obvious and obviously prominent because these people 0:16:31.000 --> 0:16:34.680 were using things like spears, So if they did have 0:16:34.760 --> 0:16:39.320 a hand preference, then a spear would definitely develop that 0:16:39.680 --> 0:16:42.920 arm connected to that hand, and it would stay in 0:16:42.960 --> 0:16:46.800 the fossil record through the skeletons. Right. They also have 0:16:46.880 --> 0:16:50.320 looked at other fossils as far back as one point 0:16:50.400 --> 0:16:53.920 six million years. There's a skeleton called, I want to say, 0:16:53.960 --> 0:16:57.040 the Kokomo Boy. Even though it's not, but I love 0:16:57.080 --> 0:17:01.480 that song. It's the Nario quote, my boy, you love Cocomo. 0:17:01.760 --> 0:17:05.760 Sure uh And he is at one point six million 0:17:05.840 --> 0:17:10.520 year old Homo air Gaster. And um, they he was 0:17:10.600 --> 0:17:13.639 clearly right handed as well. Other fossils have turned up 0:17:13.920 --> 0:17:17.560 evidence of right handedness them the teeth. Striations on the 0:17:17.560 --> 0:17:21.360 teeth suggest eating with their right hand. So what we 0:17:21.440 --> 0:17:23.560 what we can stay with a pretty decent amount of 0:17:23.560 --> 0:17:26.399 confidences that at least for the last two hundred thousand years, 0:17:26.840 --> 0:17:31.240 humanity has been a majority right handers, and there's been 0:17:31.280 --> 0:17:36.879 maybe about this constant ten proportion of left handed people, 0:17:37.240 --> 0:17:40.320 which makes the mystery even more crazy to me. Yeah, 0:17:40.359 --> 0:17:44.600 but it also makes sense that um an early tool 0:17:44.640 --> 0:17:48.280 building and teaching how to use tools, UM, I mean 0:17:48.320 --> 0:17:50.399 it holds true today. They've done studies that you know, 0:17:50.880 --> 0:17:53.040 you teach your son or daughter to tie a tie, 0:17:53.320 --> 0:17:55.840 and it's it's going to be more difficult if they're 0:17:55.920 --> 0:17:57.640 left handed and you're right handed for them to try 0:17:57.680 --> 0:18:00.520 and do it with their left hand, so or they'll 0:18:00.520 --> 0:18:03.840 pick it up easier if they go against their instinct 0:18:03.880 --> 0:18:06.919 and learn it how you've talked with. The studies have 0:18:06.960 --> 0:18:09.919 shown that so you learn faster from watching somebody and 0:18:09.920 --> 0:18:13.080 then using the same hands that they do. Yeah, and 0:18:13.200 --> 0:18:15.160 that makes sense. Back in the you know, with Took 0:18:15.160 --> 0:18:18.560 took in showing his pal how to use the bone 0:18:19.040 --> 0:18:23.439 to smash skull. You know, it's if he picks off 0:18:23.520 --> 0:18:25.800 his buddy picks up with his left hand, Took Took's 0:18:25.840 --> 0:18:29.560 gonna shake his head. No, no, yeah, use right hand 0:18:29.800 --> 0:18:31.760 or they're just gonna you know, they want. Everyone wants 0:18:31.760 --> 0:18:34.040 to fit in, even back at in the old days. Well, 0:18:34.080 --> 0:18:38.920 that's actually a suggestion of why left handedness is possibly 0:18:38.960 --> 0:18:42.440 not a little more prevalent among a certain age group 0:18:42.480 --> 0:18:46.840 today because it was equated with being weird or off 0:18:47.080 --> 0:18:53.080 or crazy or whatever. Um. And parents and teachers would 0:18:53.359 --> 0:18:56.360 force children to learn how to write with their right hand, 0:18:57.000 --> 0:19:00.840 effectively wiping out a lot of the left hand to population. 0:19:01.560 --> 0:19:05.160 Yeah and um, just jumping back a minute, I wanted 0:19:05.200 --> 0:19:09.720 to mention something important that the whole correlation versus causation thing, 0:19:10.560 --> 0:19:14.320 um with the whole language center link. Uh, it's not 0:19:14.359 --> 0:19:17.840 necessarily that that's a correlation. They appear to be strongly linked, 0:19:18.240 --> 0:19:22.440 but no one is saying that because the language hemisphere 0:19:22.480 --> 0:19:24.040 is on the left side of your brain that's causing 0:19:24.080 --> 0:19:26.879 you to be right handed right there there. And again, 0:19:26.920 --> 0:19:29.399 the reason that they are linked in a lot of 0:19:29.440 --> 0:19:35.000 scientists minds is that speech and fine motor skills are 0:19:35.160 --> 0:19:40.040 basically uniquely human, almost uniquely human. And it's just a 0:19:40.080 --> 0:19:42.879 little it's kind of like a red flag or a 0:19:42.880 --> 0:19:46.879 signal that they're both usually in the same hemisphere, and 0:19:46.920 --> 0:19:50.159 they do seem to be connected. And one hypothesis for 0:19:50.240 --> 0:19:53.720 why they're connected I thought was pretty smart. Um the 0:19:53.760 --> 0:19:59.680 idea that language spoken language emerged out of gestures hand movements, 0:20:00.000 --> 0:20:03.400 which we require fine motor skills, right, but I don't 0:20:03.440 --> 0:20:05.520 have trying to do the two legit to quit things. 0:20:06.000 --> 0:20:09.119 But the idea that language emerged out of that would 0:20:09.480 --> 0:20:12.439 suggest some sort of connection between the two, Like maybe 0:20:12.480 --> 0:20:15.119 the fine motor skill section is the more ancient of 0:20:15.119 --> 0:20:18.800 the two, and then language evolved out of that. But 0:20:18.880 --> 0:20:21.040 we also still need our fine motor skills to like 0:20:21.280 --> 0:20:23.240 eat with a fork and knife and everything, so it's 0:20:23.280 --> 0:20:27.480 stuck around. It didn't become obsolete just because we started speaking. Yeah, 0:20:27.680 --> 0:20:30.399 I like that theory. Um. We we did mention that 0:20:30.440 --> 0:20:35.120 this is a largely uniquely human trait um, But they 0:20:35.160 --> 0:20:38.800 have followed. Uh, they've basically been looking at our closest 0:20:38.840 --> 0:20:41.359 ancestors to try and figure a lot of this stuff out. 0:20:41.400 --> 0:20:43.400 Although it did see some studies that said that, like, 0:20:44.920 --> 0:20:47.000 cats are left handed because they'll go to swat things 0:20:47.040 --> 0:20:49.920 with their left hand. But um, I'm not so sure 0:20:49.920 --> 0:20:53.440 about that. Yeah, there's not only is it difficult apparently 0:20:53.440 --> 0:20:58.720 to um test or do you attribute handedness to an animal, 0:20:59.200 --> 0:21:02.840 it's also difficult to attribute handedness to a person because 0:21:02.880 --> 0:21:05.320 the idea of whether or not you're left handed or 0:21:05.440 --> 0:21:09.600 right handed, Um, it's still questionable. Like if you write 0:21:09.600 --> 0:21:13.440 with your right hand, but you actually can write better 0:21:13.480 --> 0:21:16.280 with your left hand or something like that. Right which 0:21:16.520 --> 0:21:19.080 what are you? Yeah, is the one you're comfortable with 0:21:19.080 --> 0:21:21.760 the one that you're actually better with? Yeah, that's a 0:21:21.760 --> 0:21:24.960 good point. Um. But they have been looking at our 0:21:25.040 --> 0:21:29.239 our primate ancestors since about the nineteen twenties, and they 0:21:29.240 --> 0:21:34.080 have found patterns. Um. Apparently lemurs and are more left handed, 0:21:34.440 --> 0:21:39.440 and other prosim uh persimians um, Macaques and old World 0:21:39.520 --> 0:21:43.040 monkeys for the most part are evenly split, and gorillas 0:21:43.080 --> 0:21:47.639 and chimpanzees are about thirty five lefty. Um, But this 0:21:47.720 --> 0:21:51.240 is interesting. The more, as they say here, the more primitive, 0:21:51.240 --> 0:21:55.159 the primate, the more likely it is to be a lefty, 0:21:55.240 --> 0:22:02.000 which goes in the opposite of the gene mutation. It's 0:22:02.040 --> 0:22:05.960 the exact opposite. It implies that we were originally left 0:22:06.000 --> 0:22:09.720 handed as primates, and then as we evolved, we became 0:22:09.840 --> 0:22:12.879 right handed. So therefore right handed people are more evolved 0:22:12.880 --> 0:22:15.200 than left handed people in some weird way. Yeah. So 0:22:15.240 --> 0:22:17.760 again it's another inconsistency where and of course this is 0:22:17.760 --> 0:22:22.240 in primates too. Um, that doesn't necessarily mean it's the 0:22:22.280 --> 0:22:25.960 same thing with humans. No, definitely not. But I mean, 0:22:26.000 --> 0:22:28.000 if you're looking at our ancestry and trying to figure 0:22:28.000 --> 0:22:30.960 out where handedness came from, you have to go pretty 0:22:31.000 --> 0:22:35.479 far back right, And I that's a pretty good example 0:22:35.520 --> 0:22:41.160 of how this body of work or knowledge is very contradictory. Still, yeah, 0:22:41.240 --> 0:22:45.760 it's baffling, it's pretty awesome. Hey, Chucky, you sent me 0:22:45.840 --> 0:22:49.200 something about um ambidextrous nous. Yeah, I thought this is 0:22:49.280 --> 0:22:52.720 kind of interesting from mental flaws like, like, it was 0:22:52.800 --> 0:22:55.199 just kind of my understanding that anybody who said, oh, 0:22:55.200 --> 0:22:57.320 I'm ambidextrous knew what they were talking about. But it 0:22:57.320 --> 0:23:00.439 turns out that's really just not the case. For the 0:23:00.480 --> 0:23:04.800 most part. It's a very rare um condition. I guess 0:23:04.840 --> 0:23:08.199 you'd call it yeah, UM, because I don't know if 0:23:08.200 --> 0:23:14.080 there is as a strict definition for what constitutes being ambidextrous. 0:23:14.160 --> 0:23:18.520 Like a you know, a switch hitter in baseball doesn't 0:23:18.560 --> 0:23:21.720 necessarily mean they're ambidextrous. It means they've taught themselves to 0:23:21.840 --> 0:23:25.240 hit from the other side of the plate. Um. If 0:23:25.240 --> 0:23:28.879 you notice, as a baseball fan, you're never gonna see 0:23:28.920 --> 0:23:33.399 a player that hits uh equally as well on both sides, 0:23:34.119 --> 0:23:36.639 Like you know, the great Chipper Jones here from Atlanta, 0:23:37.080 --> 0:23:38.960 he favored one side of the plate. Although he was 0:23:39.000 --> 0:23:41.360