The Evolution of Thought Evolutionary Origins of Great Ape Intelligence Research on the evolution of higher intelligence rarely com- bines data from fields as diverse as paleontology and psychol- ogy. In this volume we seek to do just that, synthesizing the approaches of hominoid cognition, psychology, language stud- ies, ecology,evolution, paleoecology,and systematics towards an understanding of great ape intelligence. Leading scholars from all these fields have been asked to evaluate the manner in which each of their topics of research informs our understanding of the evolution of intelligence in great apes and humans. The ideas thus assembled represent the most comprehensive survey to date of the various causes and consequences of cognitive evo- lution in great apes. The Evolution of Thought will therefore be an essential reference for graduate students and researchers in evolutionary psychology, paleoanthropology, and primatology. A E. R is a professor of psychology at Glendon College of York University in Toronto. Since 1989 she has been studying intelligence and learning in ex-captive orangutans released to free forest life in central and eastern Indonesian Borneo. D R. B is a professor of anthropology at the Univer- sity of Toronto. He is a leading researcher in Miocene hominoid paleobiology. His current research interests center on the bio- geography of great ape and human origins and the relations between Miocene hominoids and the earliest humans. The Evolution of Thought Evolutionary Origins of Great Ape Intelligence Edited by Anne E. Russon Department of Psychology, Glendon College, York University, Toronto David R. Begun Department of Anthropology, University of Toronto, Toronto cambridge university press Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo Cambridge University Press The Edinburgh Building, Cambridge cb2 2ru, UK Published in the United States of America by Cambridge University Press, New York www.cambridge.org Information on this title: www.cambridge.org/9780521783354 © Cambridge University Press 2004 This publication is in copyright. Subject to statutory exception and to the provision of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published in print format 2004 isbn-13 978-0-511-19567-9 eBook (NetLibrary) isbn-10 0-511-19567-2 eBook (NetLibrary) isbn-13 978-0-521-78335-4 hardback isbn-10 0-521-78335-6 hardback Cambridge University Press has no responsibility for the persistence or accuracy of urls for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate. Contents List of contributors vii 9Evolution of complex feeding techniques in Preface ix primates: is this the origin of great ape intelligence? 140 1Evolutionary reconstructions of great ape intelligence1 . 10 The special demands of great ape locomotion and posture 172 2 Enhanced cognitive capacity as a contingent fact . of hominid phylogeny 15 . 11 Great ape social systems 190 . , PART I COGNITION IN LIVING GREAT APES , . Introduction 29 . 12 Diet and foraging of the great apes: ecological constraints on their social organizations and 3 The manual skills and cognition that lie behind implications for their divergence 210 hominid tool use 31 . 4 The cognitive complexity of social organization PART III FOSSIL GREAT APE ADAPTATIONS and socialization in wild baboons and Introduction 235 chimpanzees: guided participation, socializing . interactions, and event representation 45 13 Paleoenvironments and the evolution of adaptability in great apes 237 5 Gestural communication in the great apes 61 14 Cranial evidence of the evolution of 6 Great ape cognitive systems 76 . intelligence in fossil apes 260 . PART II MODERN GREAT APE ADAPTATION 15 Life history and cognitive evolution in the Introduction 101 apes 280 . 7 What’s in a brain? The question of a distinctive 16 Fossil hominoid diets, extractive foraging, and brain anatomy in great apes 105 the origins of great ape intelligence 298 . 8 Life histories and the evolution of large brain 17 Paleontology, terrestriality, and the intelligence size in great apes 122 of great apes 320 . v vi Contents 18 Body size and intelligence in hominoid evolution 335 . , , . PART IV INTEGRATION 19 Evolutionary origins of great ape intelligence: an integrated view 353 . . Author index 369 Species index 373 Subject index 375 Contributors . Department of Anthropology The Geological Institute of Hungary University of Toronto H-1143 Budapest Toronto, ON M5S 3G3, Canada Stefania´ ut´ 14, Hungary [email protected] kordos@mafi.hu . Department of Psychology Department of Anthropology York University Langara College 4700 Keele St Vancouver, BC V5Y 2Z6, Canada North York, ON M3J 1P3, Canada [email protected] . School of Psychology Department of Anthropology University St. Andrews Sonoma State University St. Andrews, Fife KY16 9JU, Scotland, UK Rohnert Park, CA 94928, USA [email protected] [email protected] Department of Anthropology Director, Human Origins Program 107 Swallow Hall Department of Anthropology University of Missouri National Museum of Natural History Columbia, MO 65211, USA Smithsonian Institute [email protected] Washington, DC 20560-0112, USA . [email protected] Department of Anthropology Northern Illinois University Living Links, Yerkes Primate Center De Kalb, IL 60115-2854, USA Emory University [email protected] 954 North Gatewood Road . Atlanta, GA 30329, USA Present address: Haydnstraße 25, 44147 Dortmund, Department of Anthropology, SB 130 Germany Indiana University Bloomington, IN 47405, USA [email protected] School of Life & Sport Sciences University of Surrey London, UK Department of Oral Biology, College of Dentistry [email protected] University of Illinois at Chicago 801 South Paulina St. . Chicago, IL 60612-7213, USA Department of Psychology [email protected] Glendon College, York University vii viii List of contributors 2275 Bayview Ave. University of Missouri Toronto, ON M4N 3M6, Canada Columbia, MO 65211, USA [email protected] [email protected] . Department of Anatomy Department of Anthropology Midwestern University Yale University 555 31st Street P. O. Box 208277 Downers Grove, IL 60515, USA New Haven, CT 06520-8277, USA [email protected] . Laboratory of Human Evolution Studies Biological Anthropology and Anatomy Faculty of Science, Kyoto University Duke University Sakyo-ku, Kyoto, 606-8502, Japan Box 90383 Durham, NC 27708-0383, USA [email protected] [email protected] . Graduate School of Asian and African Studies Department of Anthropology Kyoto University Department of Pathology and Anatomical Sciences Sakyo-ku, Kyoto, 606-8502, Japan 107 Swallow Hall [email protected] Preface This book arose from three realizations. First, there is picture possible today. We asked all our contributors to an important need for good models of great ape cog- explore the implications of their realm of expertise for nitive evolution. Studies of comparative primate cogni- cognition and cognitive evolution. We are grateful to all tion over the last two decades increasingly show that all of them for their willingness to embark on this enterprise great apes share a grade of cognition distinct from that and for sticking with the sometimes trying process of fit- of other nonhuman primates. Their cognition appears ting this broad range of material together.The product is to be intermediate in complexity between that of other acompilation of our contributors’ views on adaptations nonhuman primates and humans, so it offers the best relevant to cognition in the great ape lineage and our available model of the cognitive platform from which attempt to integrate their material into a coherent pic- human cognition evolved. Understanding the position ture. Our sense is that a coherent picture does emerge. of the great apes is then essential to understanding cog- That contributors working from very different perspec- nitive evolution within the primate order and ultimately, tives often voiced similar conclusions adds to our sense in humans. Second, existing reconstructions of the evo- that this picture has considerable substance. lutionary origins of great ape cognition are all in need We do not presume that our reconstruction will of revision because of advances in research on great close the book on the evolutionary origins of great ape ape cognition itself, on modern great ape adaptation, cognition. Although we covered most if not all of the and on fossil hominoids. Third, developing an accurate major issues currently recognized as important in the picture of the evolutionary origins of great ape intelli- evolution of great ape mentality, the breadth of the ma- gence requires bringing together expertise from a highly terial involved means that our coverage is inevitably diverse range of fields beyond modern great ape cogni- brief. Further, our contributors pointed to additional tion. Essential are current understandings of the brain, factors in need of consideration and there remain vast life histories, social and ecological challenges, and the areas of importance that have been little researched interactions among them in both living and ancestral or that are still crying for evidence. This picture will hominids. undoubtedly