WEBVTT - Humans Throwing Stuff 0:00:03.000 --> 0:00:05.360 Welcome to Stuff to Blow Your Mind production of My 0:00:05.480 --> 0:00:14.520 Heart Radio. Hey you welcome to Stuff to Blow Your Mind. 0:00:14.600 --> 0:00:17.680 My name is Robert Lamb and I'm Joe McCormick, and 0:00:17.720 --> 0:00:22.080 we're back with part four of our series on throwing behavior. Now, 0:00:22.079 --> 0:00:26.160 in previous parts we focused mainly on non human animals. 0:00:26.200 --> 0:00:31.120 We've looked at alleged throwing behaviors and octopuses in uh in, 0:00:31.360 --> 0:00:35.640 elephants in the mongoose. We definitely had a digression about 0:00:35.680 --> 0:00:38.479 dogs with air Bud in the previous episode. But also 0:00:38.560 --> 0:00:42.200 in the previous episode, we ended up talking about the 0:00:42.280 --> 0:00:47.080 evolution of the human capacity for throwing, which we are 0:00:47.200 --> 0:00:50.200 particularly apt at. Humans are are very good at throwing, 0:00:50.280 --> 0:00:55.080 especially compared to our nearest primate relatives. So like a 0:00:55.160 --> 0:00:58.240 chimpanzee maybe on average three or four times stronger than 0:00:58.280 --> 0:01:01.840 a human. But a human, even without specialized training, can 0:01:01.880 --> 0:01:04.720 generally throw a lot more forcefully and a lot better 0:01:04.800 --> 0:01:07.319 than a chimpanzee can. So why are we so specialized 0:01:07.360 --> 0:01:10.120 for throwing? Well, we took a look at some some 0:01:10.240 --> 0:01:14.480 evolutionary hypotheses about where our capacity for throwing comes from. 0:01:14.480 --> 0:01:17.520 But there was another thing that I came across while 0:01:17.560 --> 0:01:21.520 researching this subject that I did not get into in 0:01:21.560 --> 0:01:23.720 the previous episode, and I wanted to come back to 0:01:23.760 --> 0:01:26.759 it here because I found it really interesting. And this 0:01:26.840 --> 0:01:30.520 is the idea of what if the evolution of throwing 0:01:31.280 --> 0:01:35.240 was somehow a necessary precursor for the evolution of probably 0:01:35.280 --> 0:01:41.160 the most distinctly human trait language. Mm hmmm, So not 0:01:41.319 --> 0:01:44.440 just that humans are good at throwing and good at language, 0:01:44.480 --> 0:01:48.200 but that there is actually a a neurobiological link between 0:01:48.280 --> 0:01:51.960 the two one comes from the other. Uh So, to 0:01:52.320 --> 0:01:56.120 look at this question, I wanted to refer to a 0:01:56.160 --> 0:02:00.080 paper by William D. Hopkins, Jamie L. Russell, and Jennifer A. 0:02:00.200 --> 0:02:04.280 Schafer published in Philosophical Transactions of the Royal Society b 0:02:04.280 --> 0:02:09.280 Biological Sciences published in twenty called the Neural and Cognitive 0:02:09.320 --> 0:02:13.880 Correlates of Aimed Throwing in Chimpanzees, a magnetic residence, image 0:02:13.919 --> 0:02:17.600 and behavioral study on a unique form of social tool use. 0:02:19.080 --> 0:02:21.720 So um, to begin, they cover some of the same 0:02:21.720 --> 0:02:25.240 ground we did in the previous episode. Uh. You know 0:02:25.480 --> 0:02:29.440 how unusual human throwing behavior is in a way, and 0:02:29.480 --> 0:02:32.520 despite all the interesting examples we've discussed in these episodes 0:02:32.560 --> 0:02:35.560 of animals throwing things for various reasons, whether trained by 0:02:35.639 --> 0:02:37.600 humans or just doing it as part of their natural 0:02:37.720 --> 0:02:41.639 instinctual behaviors. UM. The authors here argued that in general, 0:02:41.880 --> 0:02:45.720 throwing remains unsystematic in their words and other animals, and 0:02:45.760 --> 0:02:49.760 I think this is fair. No other animal practices the 0:02:49.880 --> 0:02:54.560 kind of generalized, skillful habitual throwing that we do, certainly 0:02:54.560 --> 0:02:57.959 not without training by humans. Yeah, as we're discussing, the 0:02:58.000 --> 0:03:01.160 previous episode goes way back in human behavior, and it's 0:03:01.200 --> 0:03:04.560 something that even today, with all our other tools and 0:03:04.639 --> 0:03:08.600 ways of doing things at a distance, we still engage 0:03:08.600 --> 0:03:12.160 in throwing. We we I think in the very first episode, 0:03:12.160 --> 0:03:16.240 we discussed that sort of um, at least in my case, uh, 0:03:16.639 --> 0:03:19.960 the strange pull to need to throw a ball with 0:03:20.000 --> 0:03:23.160 my son when he was younger, uh, even though we 0:03:23.400 --> 0:03:26.400 were not a baseball or softball family. But it was 0:03:26.440 --> 0:03:27.920 just kind of this thing that I guess was like 0:03:27.960 --> 0:03:30.880 nostalgic and the culture, but also very satisfying to do 0:03:31.400 --> 0:03:33.680 and something that even if you're not very practiced at 0:03:33.720 --> 0:03:35.920 you can do with some or at least I found 0:03:35.920 --> 0:03:39.200 that I could do with some degree of precision. Um, 0:03:39.440 --> 0:03:42.560 despite being very rusty at the whole softball baseball thing. 0:03:43.080 --> 0:03:46.040 I totally sympathize with you there. I mean, I think 0:03:46.040 --> 0:03:48.600 neither of us are really sports guys. I don't really 0:03:48.600 --> 0:03:50.800 want rules, I don't really want teams, but I do 0:03:50.880 --> 0:03:55.480 want ball m or frisbee. Frisbee just as good in 0:03:55.520 --> 0:03:58.720 my opinion. Yeah, and I mean there's also there's there's 0:03:58.720 --> 0:04:01.440 a lot more throwing that goes on into like how 0:04:01.480 --> 0:04:03.520 often do we find ourselves across the room from someone, 0:04:03.800 --> 0:04:06.280 We request something and they give it a toss, they 0:04:06.280 --> 0:04:08.000 throw it to us, and you want to be able 0:04:08.040 --> 0:04:11.080 to catch it for various reasons. And then that's without 0:04:11.120 --> 0:04:13.160 even getting into the various sports that even if we 0:04:13.160 --> 0:04:16.480 don't engage in, we may watch, and the throwing of 0:04:17.080 --> 0:04:20.120 balls is often an essential part, or at least one 0:04:20.200 --> 0:04:23.920 aspect of a given sport. Right. But of course, apart 0:04:23.960 --> 0:04:28.560 from these recreational concerns, you know, throwing has been crucial 0:04:28.600 --> 0:04:31.719 to the survival of our ancestors. That seems pretty clear. 0:04:32.080 --> 0:04:34.200 And in the last episode we talked about arguments from 0:04:34.240 --> 0:04:39.560 evolutionary anthropology that throwing was positively selected for in human ancestors, 0:04:39.839 --> 0:04:43.360 and the bodies of hominin species like Homo erectus show 0:04:43.440 --> 0:04:49.279 anatomical changes that seem to favor forceful overhand throwing. Um, 0:04:49.360 --> 0:04:52.080 I remember those changes. They're like changes in the shoulder 0:04:52.240 --> 0:04:54.520 and the waist and the upper arm, all of which 0:04:54.880 --> 0:04:58.400 combined to allow for a more substantial wind up, sort 0:04:58.440 --> 0:05:01.479 of a pulling back of tension of of the biomechanical 0:05:01.560 --> 0:05:05.960 bowstring to be released rapidly during the throw. And we 0:05:06.040 --> 0:05:08.640 also talked about the argument that these changes appear to 0:05:08.680 --> 0:05:12.160 coincide with evidence of meat becoming a bigger part of 0:05:12.200 --> 0:05:16.440 the diet of these hominins, showing that throwing was likely 0:05:16.600 --> 0:05:21.279 useful for obtaining food, either through power scavenging like driving 0:05:21.360 --> 0:05:23.640 predators away from a kill in order to take the 0:05:23.640 --> 0:05:26.880 meat for yourself, or direct hunting uh and either way 0:05:26.920 --> 0:05:31.600 increasing the availability of food energy. Now, one very interesting 0:05:31.680 --> 0:05:35.279 thing about the adaptation for throwing is that it implies 0:05:35.360 --> 0:05:38.840 not only changes in the muscles and the skeletal system. 0:05:38.920 --> 0:05:40.880 Of course, you know, you can see all those changes 0:05:40.920 --> 0:05:43.599 around the scapula and the shoulder blade, changes in the waste, 0:05:43.680 --> 0:05:47.400 the arm, and so forth, but it also implies changes 0:05:47.520 --> 0:05:52.640 in cognition. An animal that can throw objects sourced from 0:05:52.680 --> 0:05:56.960 the environment is showing a specialized way of thinking, and 0:05:57.040 --> 0:06:00.280 not just a specialized way of moving. Now what do 0:06:00.320 --> 0:06:02.960 I mean by this? Well, as one example, the author's 0:06:03.000 --> 0:06:07.120 reference a specific captive chimpanzee who came up in the 0:06:07.160 --> 0:06:10.440 last episode, Robi, remember the story of Santino, the chimpanzee 0:06:10.440 --> 0:06:12.680 who was in a zoo and I believe Sweden was it? 0:06:13.360 --> 0:06:18.160 I believe so, Yes, Santino, Yeah, poor Santino. The author's 0:06:18.240 --> 0:06:21.640 right that Santino, who I guess was alive at the 0:06:21.680 --> 0:06:25.000 time this paper was written. Quote, hides rocks out of 0:06:25.040 --> 0:06:27.880 sight of the care staff, waiting to reveal and throw 0:06:27.920 --> 0:06:31.760 them at approaching visitors at the most opportune time. Evidence 0:06:31.760 --> 0:06:35.080 of planning comes from the observation that Santino searches for 0:06:35.320 --> 0:06:39.039 the rocks from a moat inside the enclosure prior to 0:06:39.080 --> 0:06:42.080 the arrival of the care staff and the visitors, and 0:06:42.160 --> 0:06:44.960 cashes the rocks out of sight, only to pull them 0:06:44.960 --> 0:06:48.640 out when the visitors arrive. That is a crafty chimp, 0:06:48.920 --> 0:06:52.920 and that is that is forethought. Hmm. Adding to this, 0:06:53.000 --> 0:06:57.520 the author's uh throwing their own observations of similar pre 0:06:57.600 --> 0:07:01.320 planning behavior in chimpanzees and two other research which environments, 0:07:01.360 --> 0:07:04.840 and they argue that the throwing quote, though often agonistic 0:07:04.920 --> 0:07:08.520 and function and consequence agonistic meaning a sort of confrontational 0:07:08.880 --> 0:07:13.800 aggressive behavior is not part of the apes display behavior. Indeed, 0:07:14.200 --> 0:07:17.679 most instances of aimed throwing that we have observed occur 0:07:17.800 --> 0:07:22.200 without any accompanying display behaviors such as pilo erection, hooting, 0:07:22.320 --> 0:07:26.400 and charging, further suggesting an element of planning on the 0:07:26.400 --> 0:07:29.440 part of the individual ape. Uh. So, I think that's 0:07:29.440 --> 0:07:31.600 interesting too, if you understand what they're saying there, that 0:07:31.720 --> 0:07:36.120 there is a sort of standard display behavior algorithm, like 0:07:36.160 --> 0:07:39.960 when an ape is doing an agonistic display when trying 0:07:40.000 --> 0:07:42.760 to be dominant and aggressive and maybe scare you off. 0:07:44.000 --> 0:07:46.560 It includes all of these sub features like the pilo 0:07:46.600 --> 0:07:50.440 erection meaning the bristling of body hair, hair stands on end, hooting, 0:07:50.560 --> 0:07:54.080 charging back and forth, all that stuff. And they say 0:07:54.120 --> 0:07:57.000 that when the apes throw stuff at people, they do 0:07:57.040 --> 0:07:59.880 it without all of these other features of a typical 0:08:00.040 --> 0:08:03.800 instinctual display. Another way that throwing is different from most 0:08:03.880 --> 0:08:07.080 other forms of tool use and apes. Uh. The most 0:08:07.120 --> 0:08:10.920 commonly observed types of tool use by wild chimpanzees are 0:08:11.040 --> 0:08:15.320 all things where the tool is used to extract otherwise 0:08:15.400 --> 0:08:18.720 unreachable food, often like from a whole or enclosure of 0:08:18.800 --> 0:08:22.280 some kind and then is eaten immediately. So examples here 0:08:22.280 --> 0:08:25.400 would be cracking of nuts with with stones like nutcracking 0:08:25.480 --> 0:08:28.080 is an example of ape tool use, but also termite 0:08:28.080 --> 0:08:31.560 fishing with sticks, ant dipping, and so forth. All of 0:08:31.600 --> 0:08:35.199 these give rise to an immediate food reward for executing 0:08:35.240 --> 0:08:40.240 the behavior, meaning that these behaviors are subject to regular 0:08:40.400 --> 0:08:44.320 operant conditioning rules. Uh. You know, if if a behavior 0:08:44.400 --> 0:08:47.560 leads to an immediate food reward, an animal can learn 0:08:47.640 --> 0:08:51.920 to repeat basically any arbitrary set of actions. So you know, 0:08:52.040 --> 0:08:55.560 chimpanzee gets delicious termites every time it h of course, 0:08:55.559 --> 0:08:57.360 if it if it dips for them, that's one thing. 0:08:57.360 --> 0:08:59.680 But maybe if it stands on one foot and gets 0:08:59.760 --> 0:09:02.120 term it's every time. It may learn to stand on 0:09:02.120 --> 0:09:04.640 one foot to get the meat. Yeah, and we see 0:09:04.679 --> 0:09:09.480 this reflected in so many experiments involving animals over the years. 0:09:09.520 --> 0:09:13.119 You know, can can you get an animal to manipulate 0:09:13.200 --> 0:09:15.840 some sort of technological gadget in order to get a 0:09:15.840 --> 0:09:18.960 food reward? Yeah, pressing a button or something that would 0:09:19.000 --> 0:09:22.840 have no relevance in the natural environment. So other tool 0:09:22.960 --> 0:09:26.720 use behaviors could easily be learned and reinforced through through 0:09:26.760 --> 0:09:30.160 this kind of conditioning. But throwing, as practiced by apes 0:09:30.720 --> 0:09:33.320 does not lead to an immediate food reward. In fact, 0:09:33.440 --> 0:09:37.160 it rarely, if ever, leads to a food reward at all. 0:09:38.360 --> 0:09:41.120 The author's write quote what appears to be the main 0:09:41.240 --> 0:09:45.080 reward for throwing is the simple ability to control or 0:09:45.120 --> 0:09:50.760 manipulate the behavior of the targeted individual ape or human, which, 0:09:50.840 --> 0:09:53.160 though you could consider it a goal, I mean that 0:09:53.280 --> 0:09:59.160 is much more complicated and ambiguous than a direct food reward. Yeah, 0:09:59.200 --> 0:10:03.840 because it's not the ape. And the scenario is throwing 0:10:04.040 --> 0:10:07.000 the rock, hitting the human, and then by hitting the 0:10:07.080 --> 0:10:11.400 human they drop an apple, right yeah. Now, from here, 0:10:11.440 --> 0:10:15.199 the authors go on to discuss the the underappreciated complexity 0:10:15.240 --> 0:10:17.160 of throwing. We also talked about this at length in 0:10:17.200 --> 0:10:20.880 the previous episode. But you know, suffice to say, forceful, precise, 0:10:20.960 --> 0:10:24.520 overhand throwing is an extremely demanding task, not only for 0:10:24.520 --> 0:10:28.480 the muscles but for the brain, uh, requiring split second 0:10:28.480 --> 0:10:31.440 coordination of perceptual judgments, all kinds of things. You know, 0:10:31.520 --> 0:10:34.600 how far away is the target, isn't moving in what direction? 0:10:34.640 --> 0:10:36.760 And how fast? What are the physical properties of the 0:10:36.760 --> 0:10:40.080 projectile and so forth. But then the other thing is 0:10:40.200 --> 0:10:44.960 the sequential motor control. To throw an object, you have 0:10:45.080 --> 0:10:51.160 to precisely time a rapid sequence of muscular movements, and 0:10:51.520 --> 0:10:57.040 other authors have previously suggested that quote the increased selection 0:10:57.120 --> 0:11:01.600 for neural synchrony of rapid muscular sequence routines associated with 0:11:01.640 --> 0:11:06.360 actions such as throwing are similar to the motor programming 0:11:06.440 --> 0:11:12.800 demands of language and speech, and therefore engage similar neural systems, 0:11:12.840 --> 0:11:18.520 notably broke as area. In other words, there are similarities 0:11:18.559 --> 0:11:21.200 between what the brain is doing and what parts of 0:11:21.200 --> 0:11:25.040 the brain are being used to coordinate a throw and 0:11:25.160 --> 0:11:29.840 to process language and perform speech. And one idea that 0:11:29.840 --> 0:11:33.800 gets wrapped up in this is the role of brain lateralization, 0:11:34.440 --> 0:11:38.160 segmenting of brain processes to one hemisphere or side of 0:11:38.200 --> 0:11:41.400 the brain or the other. So in cultures where throwing 0:11:41.440 --> 0:11:43.760 behavior has been studied, the authors say the majority of 0:11:43.800 --> 0:11:46.920 people pretty much always prefer to throw with the right hand. 0:11:47.640 --> 0:11:51.280 Studies in chimpanzees also show a bias toward right handedness 0:11:51.320 --> 0:11:56.559 for throwing, and these right hand preferences suggest left hemisphere 0:11:56.640 --> 0:11:59.920 dominance in the brain and these majorities of both populations 0:12:00.360 --> 0:12:02.840 because when it comes to controlling the body's movements, of course, 0:12:02.880 --> 0:12:06.280 you know the hemispheres are flipped. Generally, the left hemisphere 0:12:06.320 --> 0:12:08.280 links to the right hand and the right hemisphere to 0:12:08.320 --> 0:12:12.440 the left, and so forth. Some researchers have pointed this 0:12:12.480 --> 0:12:15.679 out in the context of the fact that the left 0:12:15.679 --> 0:12:21.199 hemisphere also contains the brain regions, notably Broca's area, that 0:12:21.320 --> 0:12:24.520 dominate the production of speech. Broca's area is also known 0:12:24.559 --> 0:12:28.480 as the motor speech area, and one researcher who has 0:12:28.520 --> 0:12:32.160 focused on this is the American neurophysiologist William H. Calvin, 0:12:32.240 --> 0:12:35.640 who was actually, I think maybe still is a professor 0:12:35.679 --> 0:12:41.040 at the University of Washington at Seattle, who, observing that 0:12:41.880 --> 0:12:44.240 pent of people prefer to throw with the right arm, 0:12:44.360 --> 0:12:49.839 Calvin hypothesized that the left hemisphere's capacity for language may 0:12:49.840 --> 0:12:54.840 have actually evolved from a pre existing adaptation for right 0:12:54.920 --> 0:12:58.920 handed throwing. He apparently published a book that contained this 0:12:59.000 --> 0:13:04.160 hypothesis in nine three. It was called The Throwing Madonna. 0:13:04.320 --> 0:13:07.240 Oh didn't they adapted this into the film? Um a 0:13:07.320 --> 0:13:12.880 lead of their own? Right? Was Madonna in that believe? So? Okay? 0:13:13.480 --> 0:13:16.600 Was she the picture in the movie? Oh? I don't remember, 0:13:16.760 --> 0:13:19.040 but I mean surely she threw a ball at least once. 0:13:19.040 --> 0:13:22.520 I mean, there's a lot of of of throwing in baseball, Yeah, 0:13:22.559 --> 0:13:24.440 you throw no matter what position you are. I guess 0:13:24.440 --> 0:13:26.880 the picture throws the most. There's no crying in baseball, 0:13:26.920 --> 0:13:29.160 but there was throwing in baseball. There's a lot that much. 0:13:29.200 --> 0:13:32.320 I remember for the film. Okay, so Madonna was definitely 0:13:32.360 --> 0:13:35.720 throwing no matter what position she played. Um no, but 0:13:36.000 --> 0:13:38.319 unfortunately did not become the basis of the movie as 0:13:38.320 --> 0:13:40.920 far as I know. Instead, it was a place where 0:13:41.200 --> 0:13:45.280 Calvin laid out an interesting, uh sort of story, a 0:13:45.360 --> 0:13:49.480 possible series of developments that could have led to the 0:13:49.520 --> 0:13:55.360 development of language via the stepping stone of of capacity 0:13:55.400 --> 0:14:00.000 for throwing. So the story goes like this, lateralization evolved 0:14:00.480 --> 0:14:05.000 for one handed throwing with the right hand, specifically so 0:14:05.080 --> 0:14:09.120 that parents, typically mothers, could cradle an infant on their 0:14:09.240 --> 0:14:13.240 left side and then they'd be free to throw with 0:14:13.360 --> 0:14:16.600 the right hand if they needed to. So, I mean, 0:14:16.800 --> 0:14:19.200 obviously things like this are hard to prove for sure, 0:14:19.280 --> 0:14:22.760 but that is an interesting idea because I started thinking 0:14:22.760 --> 0:14:27.000 about how I recently became a father, and without thinking 0:14:27.040 --> 0:14:30.000 about it at all, I pretty much always when I 0:14:30.000 --> 0:14:32.960 hold my baby, hold her on on the left side 0:14:33.160 --> 0:14:35.880 of my torso and so if she like falls asleep 0:14:35.920 --> 0:14:38.480 against me, and her head is going to be on 0:14:38.520 --> 0:14:41.880 the left side of my chest, and that from my 0:14:41.960 --> 0:14:44.440 point of view, which is also the side where the 0:14:44.480 --> 0:14:47.640 heartbeat is closer. I never planned it that way, that 0:14:47.640 --> 0:14:50.080 that just sort of happened. And I was talking to 0:14:51.040 --> 0:14:53.760 my wife and she said, yeah, most often she she's 0:14:53.800 --> 0:14:56.480 on the left side there too, So I don't know 0:14:56.520 --> 0:14:58.160 that that's kind of interesting. I mean, it could be 0:14:58.200 --> 0:15:01.600 totally unrelated, but I don't know. Yeah, yeah, yeah, yeah, 0:15:01.600 --> 0:15:04.120 I could always scoop up on the left side as well. 0:15:04.240 --> 0:15:07.040 My son is now I think finally too big for 0:15:07.080 --> 0:15:10.480 me to do that without seriously injuring myself. But yes, 0:15:11.680 --> 0:15:13.560 and I guess at a certain point you become less 0:15:13.600 --> 0:15:16.720 desiring of the heartbeat sound that like maybe loses some 0:15:16.800 --> 0:15:19.960 of the power it has over over really young infants. Yeah, 0:15:20.080 --> 0:15:22.160 I don't know. I guess it varies from from child 0:15:22.160 --> 0:15:25.360 to child, depends on how big they get and at 0:15:25.360 --> 0:15:37.480 what point they want that distance. Thank, Okay, well, so 0:15:37.560 --> 0:15:39.160 it's it's hard to know for sure if the need 0:15:39.200 --> 0:15:41.200 to scoop a child and hold them on the left 0:15:41.240 --> 0:15:43.200 side of the body close to the heartbeat is the 0:15:43.280 --> 0:15:46.920 real reason driving brain lateralization. Um, I find it more 0:15:46.920 --> 0:15:51.400 compelling than some other hypotheses that seemed to be on 0:15:51.600 --> 0:15:54.320 offer at the time. One that's sited. I was reading 0:15:54.320 --> 0:15:57.160 a review of this book by Calvin that cited a 0:15:57.200 --> 0:16:01.920 previous hypothesis that the right handedness of because um men 0:16:02.080 --> 0:16:05.520 in battle, I guess prehistoric battle needed to like hold 0:16:05.920 --> 0:16:09.200 a shield above their above their heart on the left side. 0:16:09.280 --> 0:16:13.160 I was like, I get out of here. This this 0:16:13.520 --> 0:16:17.360 discussion reminds me of a painting, might painting that I 0:16:17.400 --> 0:16:19.880 hadn't thought of in a bit, I believe. What is 0:16:19.680 --> 0:16:23.120 the title of this piece is Two Mothers by Leon 0:16:23.640 --> 0:16:28.600 Maxim of Fivery Um. That's if I'm pronouncing that correctly. 0:16:28.640 --> 0:16:31.520 It's f A I V R E. But it's a 0:16:31.560 --> 0:16:37.000 pretty stunning piece in which we see this vision of 0:16:37.000 --> 0:16:40.680 of a prehistoric mother with with very modern touches to it. 0:16:41.280 --> 0:16:43.920 But she's standing here in some sort of uh, you know, 0:16:44.520 --> 0:16:48.960 hide garment, and she has this heavy looking infant in 0:16:49.040 --> 0:16:52.480 her left arm, and then there's another child sort of 0:16:52.480 --> 0:16:55.320 hanging on to her left arm. In her right hand, 0:16:55.560 --> 0:16:59.720 she has uh sex, some sort of a a stone weapon, 0:17:00.240 --> 0:17:04.800 like a wooden wooden half with a with a stone blade, 0:17:04.880 --> 0:17:07.879 some sort of like you know, primitive axe or club. 0:17:08.320 --> 0:17:11.560 And she's staring back into the shadows behind her where 0:17:11.560 --> 0:17:14.440 this is kind of like cave environment, and there's clearly 0:17:14.680 --> 0:17:18.720 an animal lurking there, an animal emerging from the shadows. 0:17:18.720 --> 0:17:20.840 And I think this is supposed to be the other mother, 0:17:21.200 --> 0:17:23.600 the mother that is hunting her. And I have no 0:17:23.680 --> 0:17:26.480 idea of this this uh, this piece has has any 0:17:26.520 --> 0:17:28.159 connection to what we're talking about here. But it is 0:17:28.160 --> 0:17:32.480 interesting that we do see left arm cradling children, right 0:17:32.840 --> 0:17:36.879 arm brandishing a weapon to protect those children against some threat. 0:17:37.600 --> 0:17:40.040 It is a kind of beautiful painting. Yeah, her hair 0:17:40.160 --> 0:17:42.680 is perfect too, like she's really this mom's really got 0:17:42.680 --> 0:17:46.760 it together, perfect hair, protecting the children, ready to brain 0:17:46.840 --> 0:17:50.520 a panther with some sort of a stone weapon. Anyway, 0:17:50.680 --> 0:17:55.440 whatever the cause of the right hand lateralization for sequential 0:17:55.480 --> 0:17:59.520 motor control in in the throwing, uh, the the hypothesis 0:17:59.560 --> 0:18:03.959 goes on from here to suggest that sequential motor control 0:18:04.000 --> 0:18:07.320 regions that made us so good at at tossing a 0:18:07.359 --> 0:18:11.960 stone with one hand were eventually commondered by selection pressure 0:18:12.320 --> 0:18:16.280 for communication and shifted to a different kind of sequential 0:18:16.280 --> 0:18:20.080 motor control, which was language production. Now, when we think 0:18:20.119 --> 0:18:22.520 of language production, we think of speech, and that that 0:18:22.600 --> 0:18:25.840 could be the case. I think Calvin argued for a 0:18:25.880 --> 0:18:29.640 transitional stage where the original language was more gesture based, 0:18:29.720 --> 0:18:33.040 like gesturing with the hands maybe, which would have then 0:18:33.080 --> 0:18:37.320 transitioned into speech production with the mouth. Again, like many 0:18:37.359 --> 0:18:39.520 things here, that's not something we know for sure, so 0:18:39.600 --> 0:18:41.800 we're in very speculative territory. But I do find this 0:18:41.840 --> 0:18:45.040 really interesting. So again, if there's anything to this story, 0:18:45.400 --> 0:18:47.879 it would go that for some reason, there is an 0:18:47.920 --> 0:18:52.880 original right hand left brain motor lateralization for the majority 0:18:52.880 --> 0:18:56.720 of the population for throwing objects. Human ancestors get really 0:18:56.760 --> 0:18:59.119 good at throwing with that one hand, maybe cradling a 0:18:59.119 --> 0:19:02.399 baby in the other and or doing something else. And 0:19:02.440 --> 0:19:06.440 then you could argue that the lateralization for precise sequential 0:19:06.480 --> 0:19:09.960 motor activity in the left brain uh to power throwing, 0:19:10.320 --> 0:19:15.000 eventually provides the neurological scaffolding for the left brain's capacity 0:19:15.040 --> 0:19:19.360 for language and speech. Now, what was the actual experiment 0:19:19.520 --> 0:19:22.600 in this study, Well, it was looking at our closest 0:19:22.680 --> 0:19:26.800 primate relatives to see if they could provide any insight 0:19:27.000 --> 0:19:29.080 on what might have been going on in the brains 0:19:29.080 --> 0:19:34.000 of very distant human ancestors, so they were looking at chimpanzees. Now, again, 0:19:34.080 --> 0:19:37.480 chimpanzees don't throw nearly as well or as often as 0:19:37.520 --> 0:19:42.640 we do, but some throw sometimes, So what if anything 0:19:42.840 --> 0:19:46.440 is different in the brains of chimpanzees that reliably throw 0:19:46.880 --> 0:19:50.480 versus those that don't. Specifically, the authors looked at the 0:19:50.640 --> 0:19:54.160 ratio of two different types of brain tissue, white matter 0:19:54.280 --> 0:19:57.960 and gray matter in the areas of chimpanzee brains that 0:19:58.000 --> 0:20:00.879 would be most similar to the area of the human 0:20:00.880 --> 0:20:04.480 brain involved in motor control for throwing and for speech, 0:20:04.920 --> 0:20:08.040 and this would be quote the homologue to Broca's area. 0:20:08.200 --> 0:20:11.399 Remember again broke as areas involved in speech production and humans. 0:20:12.040 --> 0:20:14.200 And then they also say as well as the motor 0:20:14.359 --> 0:20:18.320 hand area of the precentral gyrus termed the knob K 0:20:18.520 --> 0:20:21.000 and O B. And what they found was that in 0:20:21.200 --> 0:20:24.560 both of these areas, in the chimpanzee equivalent of Broca's 0:20:24.600 --> 0:20:27.679 area and in the knob, the ratio of white matter 0:20:27.800 --> 0:20:32.600 to gray matter was higher in chimpanzees that throw versus 0:20:32.600 --> 0:20:37.440 those that don't. Also quote, we further found that asymmetries 0:20:37.560 --> 0:20:41.560 in white matter within both brain regions were larger in 0:20:41.600 --> 0:20:46.560 the hemisphere contralateral to the chimpanzees preferred throwing hand. So 0:20:47.440 --> 0:20:49.280 what they're saying is it's it's not just that the 0:20:49.400 --> 0:20:51.760 ratio of white matter was higher in these regions on 0:20:51.800 --> 0:20:54.600 both sides of the brain. It's that whichever hand the 0:20:54.680 --> 0:20:58.919 chimpanzee like to throw with those particular regions had a 0:20:59.000 --> 0:21:02.040 higher proportion of white matter on the opposite side of 0:21:02.080 --> 0:21:06.800 the brain. Also, they assessed the chimpanzees in this study 0:21:07.200 --> 0:21:10.679 with what is called a Primate Cognition Test BATTERY or 0:21:10.680 --> 0:21:14.240 pct B, which is, uh, you know, a sort of 0:21:14.440 --> 0:21:18.200 an s a t for for for chimpanzees, standard tests 0:21:18.240 --> 0:21:21.359 on all kinds of mental abilities, you know, uh, tons 0:21:21.400 --> 0:21:27.400 of things, spatial memory, causality, inference, tool property recognition, gaze following, 0:21:27.480 --> 0:21:30.040 and so forth. And they were looking at, well, are 0:21:30.080 --> 0:21:33.760 there any differences between apes that throw and apes that 0:21:33.920 --> 0:21:40.040 don't throw? And out of this entire test battery generally not. Generally, 0:21:40.040 --> 0:21:43.080 there were no cognitive differences except in one area. There 0:21:43.119 --> 0:21:46.800 was only one aptitude where there was a significant difference, 0:21:47.280 --> 0:21:50.600 and it was that researchers found chimpanzees that were more 0:21:50.640 --> 0:21:56.080 inclined to throw were also better at social communication. So 0:21:56.119 --> 0:21:59.399 the author's right quote these results suggest that chimpanzees that 0:21:59.440 --> 0:22:04.760 have learned throw have developed greater cortical connectivity that's correlating 0:22:04.800 --> 0:22:08.280 with the white matter between the primary motor cortex and 0:22:08.359 --> 0:22:13.240 the Broca's area. Homologue, it is suggested that during hominin evolution, 0:22:13.400 --> 0:22:16.800 after the split between lines leading to chimpanzees and humans, 0:22:17.119 --> 0:22:21.640 there was intense selection on increased motor skills associated with throwing, 0:22:22.040 --> 0:22:25.639 and that this potentially formed the foundation for left hemisphere 0:22:25.680 --> 0:22:30.560 specialization associated with language and speech found in modern humans. 0:22:31.200 --> 0:22:33.800 So this is another case where I think this is 0:22:33.840 --> 0:22:36.600 far from proven. We would need much more robust evidence 0:22:36.680 --> 0:22:41.439 before you could endorse this specific evolutionary story as as likely. 0:22:41.560 --> 0:22:45.000 But I find this very intriguing and it does seem 0:22:45.080 --> 0:22:48.919 possible to me that the capacity for throwing gave rise 0:22:49.000 --> 0:22:53.480 to the capacity for language. M So eight throws the bone, 0:22:53.760 --> 0:22:57.000 the bone spins around, the bone becomes a space station, 0:22:57.920 --> 0:23:01.480 just as Kubrick promised this. Yeah, I didn't think about that. Yeah, 0:23:02.080 --> 0:23:05.480 I want to get back into this idea of early humans, 0:23:05.600 --> 0:23:11.000 especially throwing stones as weapons and throwing other things as weapons. Uh. 0:23:11.040 --> 0:23:13.000 You know, as we discussed in the last episode, we 0:23:13.000 --> 0:23:15.480 we talked about some of the ideas concerning the development 0:23:15.480 --> 0:23:19.400 of ranged weapon technology and prehistoric humans. This idea that 0:23:19.680 --> 0:23:22.359 what first begins as a way of engaging and agonistic 0:23:22.359 --> 0:23:27.120 communication could transform into just a way of physically sending 0:23:27.160 --> 0:23:30.840 a message to another species via projectile. But then eventually 0:23:30.880 --> 0:23:33.600 that begins to get in this way to manipulate their 0:23:33.640 --> 0:23:37.560 behavior at range, especially in the case of power scavenging, 0:23:37.600 --> 0:23:39.760 and ultimately it can be used as a way to 0:23:39.880 --> 0:23:44.159 hunt prey animals. And as we were actually recording that episode, 0:23:44.520 --> 0:23:46.800 my mind kept turning to these images of some sort 0:23:46.800 --> 0:23:51.280 of prehistoric warfare scenario in which some you know, entirely 0:23:51.359 --> 0:23:56.040 to kubra cky prehistoric people were employing various weapons and 0:23:56.040 --> 0:23:58.679 and kind of probably also probably a slightly to table 0:23:58.720 --> 0:24:01.119 top war game manner or where you have you know, 0:24:01.280 --> 0:24:05.000 units of bone wielding beaters moving forward to engage in 0:24:05.080 --> 0:24:07.240 some melee attacks, and then maybe you have some units 0:24:07.240 --> 0:24:10.280 of rock throwers behind them. Um, and you know this 0:24:10.400 --> 0:24:12.480 this felt kind of silly in my head, maybe even 0:24:12.480 --> 0:24:15.760 a little Gary Larson uh esque in my head, a 0:24:15.760 --> 0:24:18.800 little far side, But then I started looking into it 0:24:18.840 --> 0:24:22.080 more because of course, you know, rock throwers were an 0:24:22.080 --> 0:24:26.080 important part of of of of our history, and when 0:24:26.080 --> 0:24:30.160 you start looking into the history of not only range weaponry, 0:24:30.200 --> 0:24:35.320