[00:09] [clangs] a historic city It is also home to Kyoto University's [00:25] Primate Research Institute. to play a game that exposes something shocking [00:39] Here is how it works. 1, 2, 3. because they're about to disappear. [00:52] in numerical order? But what if we make it harder? Get ready to point to where each number was in order... [01:05] to memorize the screen, that's fine. Or is it? to memorize the same arrangement. [01:20] Each of these puzzles is completely new but just a glance is all it needs How can a chimpanzee's memory [01:34] Well, one theory is that we humans are worse at this task because we can talk. [01:57] What makes humans different from other animals? We have the cognitive ability but also about what did happen, and what could happen. [02:14] But if language is so good, why didn't any other animal develop it like we did? from those who were almost us. [02:31] there were no chimpanzees and there were no humans. an acronym which stands for Like us, CHLCAs didn't have [02:45] great natural offenses or defenses, So living in the safety of the trees was great. Those who stayed became the chimps we know today. [03:00] some of the CHLCAs decided to venture down to the savanna. things like cooperation, imagining new strategies, [03:13] and the assigning of roles were necessary for survival, that can refer to things across time: Many different types of creatures emerged [03:27] But today, only one member of the family remains. Language as we know it may have been one of the strategies But where did it move in? [03:42] and those who didn't aren't totally different. A brand-new brain structure didn't just pop into existence. must have been sacrificed. [03:57] detailed short-term memory in return for language. is the Cognitive Tradeoff Hypothesis. [04:25] is the culmination of decades of work Professor Tetsuro Matsuzawa Founded in 1967, [04:39] in association with the nearby Japan Monkey Center. and nearly 1,000 primates who live and play in open spaces. [04:54] [monkeys chitter] [05:08] Is there a baby on that one? [gibbers] [05:23] That's where they live. [grunts] researching non-human primates. [05:38] and here in Japan, designed to mimic life in the wild. set high atop the chimpanzee'' climbing structure. [05:55] chimpanzees are free to come and go as they please. If they decide to stay, designed to mimic foraging behavior. [06:09] When the chimpanzees are interested in participating, where a camera uses facial recognition software based that particular chimp's current familiarity [06:24] as it would for a chimp to forage a single bite. is accounted for in their diet. No human even needs to be...? [06:41] similar in many ways to what they would be doing in the wild. Dr. Matsuzawa has been running memory tests like these [06:54] His research has shown the phenomenal of these primates. Two of the most famous chimps at the PRI are Ai, [07:08] and her son Ayumu, whose name means "walk." by studying chimpanzees like them? If we and chimpanzees come from a common ancestor, [07:24] what can explain the split where the chimpanzees don't seem to need or to develop language Why would that happen? Was it an accident? [07:53] Ah-ha. [08:09] provided a pressure to develop language. Yes. So, in a way, we should be really grateful [08:24] they got pushed out of the trees. [08:37] -Bang, bang. -[laughs] but you don't have language. [08:53] Right now. [09:09] Quick decisions. Our ancestors didn't have that same pressure? [09:27] Hmm. [09:54] suggests that in the dangerous world beyond the trees, early humans needed to teach each other but to hypotheticals and generalities. [10:10] meant sacrificing the immediate and detailed memory of their ancestors. [10:22] Yeah. I'm able to describe things in an abstract way. [10:38] So it seems like a pretty good trade-off. Yeah. [10:56] Yeah. Sharing is what makes us "us." [11:13] I would love to see your working memory tests I would also really love to participate myself Yes. [11:26] compete like that together? -about the idea too. -[laughs] [gibbering] [11:47] [Michael] An opportunity to do the memory task just like a chimpanzee Let's see who shows up. [11:59] You're really good at this, Ai. Ai is older now, and just like in humans, So I may actually stand a chance. [12:19] I will be sitting in the booth next to her. Normally, her son Ayumu plays against her. I'm not your child, though, am I? [12:34] How will my memory compare to that of a chimp [exhales] where each of the three numbers are in numerical order. [12:50] as soon as I touch one of them on the screen, so I can no longer see where they are. [Tetsuro] Okay, let's go. [13:11] I get an error noise like this... sounds like this. they are rewarded with apples. [13:25] I'm not getting apples. You really actually have to focus more than I expected. [13:37] [buzzer] [computer chirps] [13:50] [Tetsuro] 95. [14:03] I've managed to beat Ai. How many symbols? [14:24] This is a lot harder. but starts a little bit differently. This time, three numbers appear on a blank screen, [14:37] the entire screen is covered in boxes. [computer chirps] Whew. [14:52] [buzzer] [buzzer] [15:12] you having fun? -Whoa! -[grunts] [15:25] Ai is used to Ayumu, her son, playing the game beside her, so my presence may be throwing her off. It was fun squaring off against Ai, [15:37] but I want to see how I would do against her son, Ayumu. Okay... [15:49] able to ace the memory tests at blazingly fast speeds. But today, Ayumu is not interested in mental combat. [16:02] who live with him here at the PRI. of Matsuzawa's research, we can't make him join us. for me to compete against him. [16:17] with nine numerals. as it was against Ai. [16:32] Oh, man. -[buzzer] -Wow. Even when I take time I can't do it right. [16:50] Okay, more time. I thought I had that one. [17:06] It takes a long time to memorize nine numerals' positions. It's embarrassing how long this takes me. [17:21] I can do this one. All right. Yeah. [17:40] You don't need to laugh about it. Thirteen. [17:52] I got better, yeah, because you were pressuring me. Six times worse, six times slower. [18:06] Yeah. I would love to. [Michael] This is the most difficult test. at Ayumu's speed, [18:21] but now I have to memorize them all it takes to blink. So I get half a second to prepare? [18:36] As a reminder, this is how Ayumu performs, which is standard for a young chimp. -That's way too fast. -[buzzer] [18:49] I got the first three. [buzzer] [19:02] [laughs] I don't know where the 2 is. Trying to think of this very holistically. [19:18] [clears throat] if I see them, I'm just having to guess. [19:36] [buzzer] Yeah. It's impossible. [19:53] It was the first time you had had a chimpanzee and a human What do you think--? If you ever need me to study as a primate, [20:08] -I give myself to you. -Okay. [20:20] Wow. [21:02] And we need to make sure to preserve them. And yet they are our closest link to understanding [Tetsuro] Mm. [21:17] -[Tetsuro] Mm, right. -[Michael] Quite literally. [snarling] [21:34] use complex symbolic language doesn't make us any better than any other species. In fact, in some ways we aren't better, [21:48] Today, we study those who took different paths If we lose them, we lose part of our story, who we are, [22:03] [gibbering] And, as always, This season, on Mind Field. [22:20] I want to perform a reverse exorcism. There was like a glowing figure, man. [22:33] I would love to do the Stanford prison experiment again. [electricity hums] [22:45] You having fun? [shrieks] function like a brain. [22:57] Doing a good moral deed can actually make you more likely We're going to see if we can get people to allow a child [23:10] -How old are you, son? -Twelve. This facility is where you both cryo-preserve people We have 159 patients in these tanks. [23:24] We're offering an unknown extension of human lifespan. That's pretty spooky. Please figure out what this message is saying. [23:40] -[man] You ready? -I'm ready. [24:10] but you can come with me. I'll see you there.