The Alex Studies: Cognitive and Communicative Abilities of Grey Parrots

448 Pages·1999·1.44 MB·English

by  Irene Maxine Pepperberg

THE ALEX STUDIES

THE ALEX STUDIES
Cognitive and Communicative
Abilities of Grey Parrots
IRENE MAXINE PEPPERBERG
HARVARD UNIVERSITY PRESS
Cambridge,Massachusetts,and London,England
Copyright(cid:2)1999byIreneMaxinePepperberg
Allrightsreserved
PrintedintheUnitedStatesofAmerica
First Harvard University Press paperback edition, 2002
LibraryofCongressCataloging-in-PublicationData
Pepperberg,IreneM.(IreneMaxine)
TheAlexstudies:cognitiveandcommunicative
abilitiesofgreyparrots/IreneMaxinePepperberg.
p. cm.
Includesbibliographicalreferences.
ISBN0-674-00051-X (cloth)
ISBN0-674-00806-5 (pbk.)
1. Africangreyparrot—Behavior. 2. Cognition
inanimals. 3. Animalcommunication. I. Title.
QL696.P7P46 1999
598.7(cid:3)1—dc21 99-29630
DesignedbyGwenNefskyFrankfeldt
To my father, Robert Platzblatt, forhisloveandencouragement,
to Alex, the raison d’ˆetre, and to Griffin, Kyaaro, and Alo,
for their supporting roles

CONTENTS
PREFACE ix
1 Introduction:In Search of King Solomon’sRing 1
2 Can We ReallyCommunicatewith a Bird? 13
3 Can a Parrot Learn ReferentialUse of EnglishSpeech? 36
4 Does a Parrot Have CategoricalConcepts? 52
5 Can a Parrot Learn the Conceptof Same/Different? 62
6 Can a Parrot Respondto the Absenceof Information? 80
7 To WhatExtentCan a Parrot Understandand Use
NumericalConcepts? 96
8 How Can We Be Sure That Alex Understandsthe Labels
in His Repertoire? 125
9 Can a Parrot UnderstandRelativeConcepts? 152
10 WhatIs the Extentof a Parrot’sConceptof Object
Permanence? 168
11 Can Any Part of a Parrot’sVocal BehaviorBe Classifiedas
‘‘Intentional’’? 197
12 Can a Parrot’sSound PlayAssistIts Learning? 209
13 Can a Parrot’sSound PlayBe Transformedinto Meaningful
Vocalizations? 231
14 WhatInput Is Neededto Teach a Parrot a Human-based
CommunicationCode? 249
15 How Similarto Human Speech Is That Producedby a Parrot? 272
16 How Does a Grey Parrot ProduceHuman SpeechSounds? 288
17 Conclusion:What Are the Implicationsof Alex’sData? 321
NOTES 329
REFERENCES 347
GLOSSARY 409
CREDITS 411
INDEX 413

PREFACE
‘‘Bye. I’m gonna go eat dinner. I’ll see you tomorrow.’’ I hear these
words,orvariations,eachnightasIleavemylaboratory.Exactlywhat
one expects to hear from the typical graduate or undergraduate stu-
dent—but these words do not emanate from human lips; rather they
come from a beak—thebeak of my researchsubject,a Grey parrot.
Notmanyscientistscandescribesuchinteractionswiththesubject
of their studies, but for the past two decades I have been examining
thecognitiveandcommunicativeabilitiesofthisparrot,Alex,andthe
dialogue quoted above is one outcome of my work. In recent years,
AlexhasbeenjoinedbyKyaaro,Griffin,and,briefly,Alo.WhenIbegan
my studies, the capacities of Grey parrots were unknown. Yes,every-
one knew parrots could mimic human speech sounds, often to an
uncanny extent. And in articles in the popular press, pet owners
claimed that their birds used speech in meaningful ways. Was therea
kernel of truth in all this anecdotal evidence? How much did these
birds really understand? How much could these birds learn to under-
stand? Given an appropriately enriched environment, might parrots
turnouttobethegreatapesofthebirdworld?Isetouttofindanswers
to these questions.
Thatundertakinghasgeneratedanimmenseamountofdata,andin
this book I attempt to integrate these data into a coherent whole. In
the course of my research, I have had to delve into comparative and
cognitive psychology, animal learning, ethology,evolutionarybiology,
linguistics,andevenneurobiology,andhavepublishedjournalarticles
andbookchaptersrelatedtothoseareas.Thesepublications,however,
failtoprovideanoverallpicture:Theyprovidemomentarysnapshots,
rather than a cohesive album, of the capacities of Alex and my other
birds. I hope that this bookprovidestheappropriatepanoramicview
of my data. This book is not, however, meant to be a detailed review