[00:00.00]Narrator: Listen to part of a lecture in a linguistics class.[00:05.90]The professor has been discussing animal communication systems.
[00:11.18]FEMALE PROFESSOR: OK, so last time we covered the dances honeybees do to indicate where food can be found, and the calls and songs of different types of birds… [00:21.11]Today I'd like to look at-at some communication systems found in mammals—uh, particularly in primates such as, uh, orangutans, chimpanzees, gorillas…um, [00:33.36]yes, Thomas?
[00:35.08]MALE STUDENT: Excuse me, professor, [00:37.89]but…when you talk about gorilla language, do you mean, like, those experiments where humans taught them sign language, or-or a language like…
[00:46.86]FEMALE PROFESSOR: OK, OK, wait-wait-wait just a minute—[00:49.14]now, who in this class heard me use the word “language”? [00:54.56]No one, I hope—[00:56.27]what we’re talking about here are systems of communication, alright?
[01:00.73]MALE STUDENT: Oh, sorry, communication, right…uh, [01:03.19]but could you maybe, like, clarify what the difference is?
[01:07.99]FEMALE PROFESSOR: Of course, that’s a fair question… [01:10.40]OK, well, to start with, let's make it clear that language is a type of communication, not the other way around. [01:17.99]OK, so all communication systems, language included, have certain features in common. [01:24.72]For example, the signals used to communicate—from the bees'dance movements to the words and sentences found in human language—
[01:33.02]all these signals convey meaning. [01:36.26]And all communication systems serve a purpose—a, uh, pragmatic function of some sort—warning of danger, perhaps, or offering other needed information.[01:46.97]But there are several features peculiar to human language, that have, for the most part, never been found in the communication system of any other species.
[01:57.68]For one thing, learnability: [02:01.08]Animals, uh, animals have instinctive communication systems; [02:06.24]um, when a dog, a puppy gets to a certain age, it's able to bark. [02:11.21]It barks without having to learn how from other dogs. It just... barks. [02:15.98]But much of human language has to be learned, from other humans. [02:20.20]What else makes human language unique? [02:22.66]What makes it different from animal communication? Debra.
[02:27.64]FEMALE STUDENT: Uh, how about grammar? [02:31.41]Like, having verbs, nouns, adjectives…
[02:34.49]FEMALE PROFESSOR: OK, that's another feature [02:36.41]and it's a good examp—
[02:37.32]FEMALE STUDENT: …I mean, I mention this 'cause, like, in my biology class last year, I kinda remember talking about a study on prairie dogs, where…I think…the researchers claimed that the warning cries of prairie dogs constitute language because they have these different parts of speech—[02:54.66]you know, like nouns to name the type of predator they’ve spotted, uh, adjectives to describe its size and shape, verbs, um… but now it seems like—
[03:04.76]FEMALE PROFESSOR: Alright, hold on a moment… [03:05.97]I'm familiar with the study you're talking about—[03:08.21]and for those of you who don't know, prairie dogs are not actual dogs; [03:12.73]they’re a type of rodent who-who burrow in the ground in the grasslands of the western United States and Mexico.
[03:19.72]And, uh—in this study, the researchers looked at the high-pitched barks a prairie dog makes when it spots a predator. [03:28.34]And from this they made some pretty—well, they made some claims about these calls qualifying as an actual language, with its own “primitive” grammar. [03:38.91]But actually these warning calls are no different from those found among certain types of monkeys. [03:44.42]And—well, let’s not even get into the question of whether concepts like “noun” and “verb” can be meaningfully applied to animal communication.
[03:52.52]Another thing that distinguishes a real language is a property we call discreteness. [03:58.58]In other words, messages are built up out of smaller parts—sentences out of words, words out of individual sounds, etc. [04:07.98]Now maybe you could say that the prairie dog’s message is built from smaller parts.
[04:13.94]Like, say for example our prairie dog spots a predator—a big coyote, approaching rapidly. [04:20.21]So the prairie dog makes a call that means “coyote,” then one that means “large,” and then another one to indicate its speed. [04:28.15]But do you really suppose it makes any difference what order these calls come in? No.
[04:35.04]But the discrete units that make up language can be put together in different ways…[04:42.51]those smaller parts can be used to form an infinite number of messages—including messages that are completely novel, that’ve never been expressed before. [04:52.41]For example, we can differentiate between “A large coyote moves fast” and, say, um, hmm… “Move the large coyote fast,” or “Move fast, large coyote!”—and I truly doubt whether anyone has ever uttered either of these sentences before. [05:11.41]Human language is productive—an open-ended communication system—whereas no other communication system has this property.
[05:21.18]And another feature of language that’s not displayed by any form of animal communication is what we call displacement—[05:29.74]that is, language is abstract enough that we can talk about things that aren’t present here and now—[05:36.80]things like, “My friend Joe is not in the room,” or “It’ll probably rain next Thursday.” [05:43.69]Prairie dogs may be able to tell you about a hawk that’s circling overhead right now, but they’ve never shown any inclination to describe the one they saw last week.