The Cognitive Tradeoff Hypothesis

[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.