SCIENTIFIC mER-- OFFPRINTS Teaching Language to an Ape by Ann James Premack and David Premack SCIENTIFIC s/ilYIERI~ OCTOBER 1972 VOL. 227. NO.4 PP.92-99 ’ _’ II - PUBLISHED BY W. H. FREEIVMN AND COMPANY &jO MARKET STREET, SAN FRANCISCO, CALIFORNIA 94104 Copyright 0 1972 by Scientific American, Inc. All rights reserved. Printed in the U.S.A. No part of this offprint may be reproduced by any mechanical, photographic or electronic Process, or in the form of a phonographic recording, nor may it be stored in a retrieval system, transmitted or otherwise copied for public or private use without written permission of the publisher. - c y at Teaching Language to anApe l ‘1 Sarah, a young chimpanzee, has a reading and writing vocabulary of about 130 Qords.” Her understanding-goes beyond the meaning of words and includes the concepts of class and sentence structure by Ann James Premack ind David Premack ver the past 40 years several ef- derstand about 100 words, but she never recently Allen and Beatrice Gardner forts have been made to teach a did try to speak them. In the 1940’s have taught their chimpanzee Washoe 0 chimpanzee human language. In Keith and Cathy Hayes raised a chim- to communicate in the American Sign the early 1930’s Winthrop and Luella panzee named Vicki in their home; she Language with her fingers and hands. Kellogg raised a female chimpanzee learned a large number of words and Since 1966 in our laboratory at the Uni- named Gua along with their infant son; with some difficulty could mouth the versity of California at Santa Barbara at the age of 16 months Gua could un- words “mama,” “papa” and “cup.” More we have been teaching Sarah to read and write with variously shaped and colored pieces of plastic, each repre- senting a word; Sarah has a vocabulary of about 130 terms that she uses with a reliability of between 75 and 80 percent. Why try to teach human language to an ape? In our own case the motive was to better define the fundamental nature of language. It is often said that lan- guage is unique to the human species. Yet it is now well known that many oth- er animals have elaborate communica- tion systems of their own. It seems clear that language is a general system of which human language is a particular, albeit remarkably refined, form. Indeed, it is possible that certain features of hu- man language that are considered to be uniquely human belong to the more gen- eral system, and that these features can be distinguished from those that are - unique to the human information-proc- - essing regime. If, for example, an ape cau be taught the rudiments of human language, it should clarify the dividing line between the general system and the human one. here was much evidence that the Tchimpanzee was a good candidate for the acquisition of language before we began our project. In their natural en- ( vironment chimpanzees have an exten- sive vocal “call system.” In captivity the SARAH, after reading the message “Sarah insert apple pail banana dish” on the magnetic chimpanzee has been taught to sort pie- board, performed the appropriate actions. To be able to make the correct interpretation tures into classes: animate and inani- that she should put the apple in the pail and the banana in the dish (not the apple, pail and mate, old and young, male and female. banana in the dish) the chimpanzee had to understand sentence structure rather than just Moreover, the animal can classify the word order. In actual tests most symbols were colored (see iEZustration on opposite page). same item in different ways depending 2 NOUNS SARAH MARY PAIL . DISH CHOCOLATE APPLE BANANA APRICOT RAISIN VERBS GIVE TAKE INSERT WASH :ONCEPTS/CONDITIONALS SAME DIFFERENT NO-NOT NAME OF COLOR OF A? IF-T&N ADJECTIVES (COLORS) RED GREEN PLASTIC .SYMBOLS that varied in color, shape and size were cept. A “Chinese” convention of writing sentences vertically from chosen as the language units to be taught to Sarah. The plastic top to bottom was adopted because at the beginning of her training pieces were backed with metal so that they would adhere to a mag- Sarah seemed to prefer it. Sarah had to put the words in proper se- netic board. Each plastic symbol stood for a specific word or con- quence but the orientation of the word symbols was not important. 3 SAME DIFFERENT CONCEPTS “SAME” AND “DIFFERENT” were introduced into were placed before her and she was given plastic word for “same” Sarah’s vocabulary by teaching her to pair objects that were alike and induced to place word between the two objects. She was also (top illustration). Then two identical objects, for example apples, taught to place the word for “different” between unlike objects. DiFFERENT SAME SAME DIFFERENT THE INTERROGATIVE was introduced with the help of the con- tion mark” was placed between two objects and Sarah had to re- cepts “same” and “different.” A plastic piece that meant “ques- place it with either the word for“same” or the word for “different.” SAME DIFFERENT - - ?- NEW VERSION OF THE INTERROGATIVE was taught by ar- [Object Al the same as?” or “What is [Object A] different from?” ranging an object and plastic symbols to form questions: “What is Sarah had to replace question marker with the appropriate object. 4 on the alternatives offered. Watermelon her reach. To obtain the fruit Sarah now between pairs of objects. Thjs ~1~~~~~ is class&xl as fruit in one Set of alterna- had to put the plastic piece on a “lan- shape (which bore no resemblance to the tives, as food in another set and as big guage board” on the side of her cage. usual kincl of question mark) made the in a third set. On the basis of these dem- (The board was mngnetic and the plastic; question es$icit rather than illlplicit, as onstrated conceptual abilities we made square was backecl witli a thin piece of it had been in the simple matelling tests. the assumption that the chimpanzee steel so that it would stick.) After Sarah When tJ)e interrogative element \vas could be tnuSht not only the names of had learned this routine the fruit was placed L)etweeu a pair of cups, jt lne;lllt; specific n~emlxxs of a class but also the changed to an apple and she had to “What is tlze relation between cup A and names for the classes themselves. place a blue plastic word for apple on cup B?” The choices provided Sar:lJl It is not necessary for the names to be the board. Later several other fruits, the were the plastic words “same” and “dif- vocal. They can just as well be based verb “give” and the plastic words that ferent.” She learned to remove the in- on gestures, written letters or colored named each of them were introduced. terrogative particle and substitute the stones. The important thing is to shape To be certain that Sarah knew the correct word [see to)) Illnstrntiotz OIZ op.. the language to fit the itlfolmation-proc- meaning of “give” it was necessary to p05itc fMgc]. Sarah was able to transfer essing capacities of the chimpanzee. To contrast “give” with other verbs, such what she had learned and apply the a large extent teaching language to an as “wash,” “cut” and “insert.” When word ‘same” or “differeilt” to numerous animal is simply mapping out the con- Sarah indicated “Give apple,” she was pairs of objects that had not been used in ceptual structures the animal already given a piece of apple. When she put her training. possesses. By using a system of naming “Wash apple” on the board, the apple Any construction is potentially a ques- that suits the chimpanzee we hope to was placed in a bowl of water and tion. From the viewpoint of structural find out more about its conceptual world. washed. In that way Sarah learned what linguistics any construction where one Ultimately the benefit of language es- action went with what verb. or more elements are deleted becomes a r periments with animals will be realized In the first stage Sarah was required question. The constructions we used in an understanding of intelligence in to put only one word on the board; the with Sarah were “A same A” and “‘A dif- terms not of scores on tests but of the name of the fruit was a sufficient indi- ferent B.” Elements in these construc- underlying brain mechanisms. Only then cator of the social transaction. When tions were removed and the deletion was can cognitive mechanisms for classify- names for different actions-verbs-were marked with the interrogative symbol; ing stimuli, for storing and retrieving in- introduced, Sarah had to place two Sarah was then supplied with a choice formation and for problem-solving be words on the board in vertical sequence. of missing elements with which she studied in a comparative way. In order to be given an apple she had to could restore the construction to its fa- The first step in teaching language is write “Give apple.” When recipients miliar form. In principle interrogation to exploit knowledge that is already were named, two-word sentences were can be taught either by removing an present. In teaching Sarah we first not accepted by the trainer; Sarah had element from a familiar situation in the mapped tile simple social transaction of to use three words. There were several animal’s world or by removing the ele- giving, which is something the chimpan- trainers, and Sarah had to learn the ment from a language that maps the an- zee does both in nature and in the labo- name of each one.