Great apes' causal cognition in the physical domain [Elektronische Ressource] / Daniel Hanus

Daniel Hanus

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Humboldt-Universität zu Berlin Dissertation Great Apes’ Causal Cognition in the Physical Domain Zur Erlangung des akademischen Grades Doctor rerum naturalium Mathematisch-Naturwissenschaftliche Fakultät II Daniel Hanus Dekan: Prof. Dr. Peter Frensch Gutachter: 1. Prof. Dr. Elke van der Meer, Humboldt-Universität, Berlin 2. Prof. Dr. Michael Tomasello, Max Planck Institut für evolutionäre Anthropologie, Leipzig 3. Dr. Josep Call, ionäre Anthr eingereicht: 04. August 2009 Datum der Promotion: 03. Dezember 2009 1Table of content Zusammenfassung .................................................................................................................... 4 Summary ................................................................................................................................... 5 Acknowledgements ................................................................................................................... 6 List of original publications ..................................................................................................... 7 GENERAL INTRODUCTION ............................................................................................... 8 Prologue ................................................................................................................................. 8 General approach ..............................................................................

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• Psychologie

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• Publié par: humboldt-universitat_zu_berlin
• Publié le: 01 janvier 2009
• Nombre de lectures: 60
• Langue: English
• Poids de l'ouvrage: 1 Mo

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Humboldt-Universität zu Berlin

Dissertation

Great Apes’ Causal Cognition in the Physical Domain

Zur Erlangung des akademischen Grades Doctor rerum naturalium

Mathematisch-Naturwissenschaftliche Fakultät II

Daniel Hanus

Dekan: Prof. Dr. Peter Frensch

Gutachter: 1. Prof. Dr. Elke van der Meer, Humboldt-Universität, Berlin 2. Prof. Dr. Michael Tomasello, Max Planck Institut für evolutionäre Anthropologie, Leipzig 3. Dr. Josep Call, Max Planck Institut für evolutionäre Anthropologie, Leipzig eingereicht: 04. August 2009 Datum der Promotion: 03. Dezember 2009

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Table of content Zusammenfassung ................................................................................................................... 4 Summary .................................................................................................................................. 5 Acknowledgements .................................................................................................................. 6 List of original publications..................................................................................................... 7 GENERAL INTRODUCTION ............................................................................................... 8 Prologue ................................................................................................................................. 8 General approach.................................................................................................................... 9 Causal cognition in children................................................................................................. 10 Causal cognition in animals ................................................................................................. 13 Causal cognition in primates ................................................................................................ 14 Outline studies...................................................................................................................... 16 STUDY I.................................................................................................................................. 18 Comparing the performances of apes and humans in the floating peanut task ............... 18 Abstract ................................................................................................................................ 19 Introduction .......................................................................................................................... 20 Experiment 1: ......................................................................................................................... 22 Leipzig chimpanzees and gorillas ........................................................................................ 22 Method ................................................................................................................................. 22 Subjects ............................................................................................................................ 22 Apparatus and procedure.................................................................................................. 22 Results .................................................................................................................................. 23 Discussion ............................................................................................................................ 23 Experiment 2: ......................................................................................................................... 25 Sanctuary orangutans and chimpanzees ............................................................................... 25 Method ................................................................................................................................. 25 Subjects ............................................................................................................................ 25 Apparatus and procedure.................................................................................................. 25 Experimental phase .......................................................................................................... 26 Control phase.................................................................................................................... 26 Results .................................................................................................................................. 27 Experimental phase .......................................................................................................... 27 Control phase.................................................................................................................... 28 Discussion ............................................................................................................................ 30 Experiment 3: ......................................................................................................................... 32 Functional fixedness............................................................................................................. 32 Method ................................................................................................................................. 32 Subjects ............................................................................................................................ 32 Apparatus and procedure.................................................................................................. 33

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Results .................................................................................................................................. 33 Discussion ............................................................................................................................ 35 Experiment 4: ......................................................................................................................... 36 Children ............................................................................................................................... 36 Method ................................................................................................................................. 36 Participants ...................................................................................................................... 36 Apparatus and procedure.................................................................................................. 36 Results .................................................................................................................................. 37 Discussion ............................................................................................................................ 38 General discussion................................................................................................................ 39 STUDY II ................................................................................................................................ 46 Contrasting the use of causal and arbitrary cues in chimpanzee problem solving.......... 46 Abstract ................................................................................................................................ 47 Introduction .......................................................................................................................... 47 Method ................................................................................................................................. 49 Subjects ............................................................................................................................ 49 Materials .......................................................................................................................... 49 Procedure ......................................................................................................................... 49 Results .................................................................................................................................. 51 Discussion ............................................................................................................................ 53 STUDY III............................................................................................................................... 56 Chimpanzees infer the location of a reward on the basis of the effect of its weight ........ 56 Original article........................................................................................................................ 57 Supplemental data.................................................................................................................. 62 Experimental methods.......................................................................................................... 62 Subjects ............................................................................................................................ 62 Materials .......................................................................................................................... 62 Procedure ......................................................................................................................... 62 Analysis details .................................................................................................................... 63 GENERAL DISCUSSION..................................................................................................... 65 Study summaries .................................................................................................................. 65 Ontogenetic origins of causal cognition............................................................................... 67 Associative learning and causal reasoning........................................................................... 68 Unique human causal cognition? ......................................................................................... 69 Final conclusion and outlook ............................................................................................... 71 Epilogue ............................................................................................................................... 72 REFERENCES ...................................................................................................................... 73

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Zusammenfassung Diese Dissertation beschäftigt sich m it Kausalkognition bei nich tmenschlichen Prim aten. Es wurden drei experim entelle Paradigm en verw endet, um zu beleuchten, wie Menschenaffen physische Beziehungen zwischen Objekten verstehen. In der ersten Studie ( STUDIE I itpansen, Gorillas, Orang-Utans und Kinder m ) wurden Schim einem Problem konfrontiert, dessen Lösung die Verwendung eines f lüssigen Werkzeugs (Wasser) erforderte. Einige der Schim pansen und Kinder entdeckten „einsichtsvoll“ eine Lösung, um an eine Belohnung (Erdnuss) zu gela ngen, die sich außerh alb ihrer Reichweite befand. Verschiedene Kontrollbedingungen unt ermauerten die Zielgerichtetheit des Verhaltens der Schim pansen. Die getesteten Go rillas und die Orang-Utans waren nicht in der Lage, die Aufgabe zu lösen. Zwei weitere Studien widm eten sich der Frage, ob Schim pansen Gewicht als kausal relevantes Unterscheidungs-m erkmal nutzen können. In STUDIE II war es Aufgabe der Schimpansen aus insgesam t fünf in Form und Größe identischen F laschen diejenige zu finden, die als einzige Fruchtsaft enthielt. Die Saftflasche untersch ied sich dabei entweder durch ihr Gewicht (k ausales Merkmal) oder durch ih re Farbmarkierung (arbiträres Merkmal) von den anderen Flaschen. Es zeigte sich, dass das Suchverhalten der Testtiere stark von der Art des jew eiligen Me rkmals beein flusst wa r. Während Schim pansen schnell lernten, die Saftflasche aufgrund ihres kausal relevanten Merkmals zu identifizieren, gelang ihnen dies nicht anhan d des arbiträren Hinweisreiz es. STUDIE II I fokussierte noch detaillierter auf die Unterscheidung zwischen Ereignisketten, die entweder in arbiträrem oder kausalem Zusammenhang standen. Die Schimpansen ware n hier aufgefordert, durch rein passives Beobachten den Aufenthaltsort einer Futterbelohnung (Banane) herauszufinden. Dazu wurden zwei verschiedene Ereignisfolgen präsentiert: eine kausal informative Abfolge (hervorgerufen durch die physische Wirkung des Futters) und eine rein arbiträre Abfolge (hervorgerufen durch ein Ereignis, dass in ke inerlei kausalem Zusammenhang zum Futter stand). Auch hier waren Schimpansen nur dann erf olgreich, w enn die Testsituation ka usale Rückschlüsse ermöglichte, während es ihnen anderseits nich t gelang, nützliche Schlu ssfolgerungen aus rein arbiträren Zusammenhängen zu ziehen. Beme rkenswerterweise unterschied en die Tiere offensichtlich zwischen zwei Testsituationen, die perz eptuell nahezu id entisch, kon zeptuell jedoch sehr verschieden waren. Zusammenfassend lassen sich d ie Daten dahingehend interpreti eren, d ass – ähn lich wie bei Menschen – die kausale Kognition bei Schim pansen nicht nur auf rein perzeptuellen Informationen, sondern zudem auf strukturel len Abstraktionen ihre r physischen Um gebung beruht. Es wird allerdings verm utet, dass Mensch en als einzige Art in der Lage sind, darüber hinaus rein symbolische Informationen zu konzeptualisieren.

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Summary This thesis focused on the topic of causal c ognition in nonhuman primates. For that purpose, I applied three experimental paradigms to test different aspects of gr eat apes’ understanding of physical object–object relations. In the first study ( STUDY I rillas, orang utans, and hum an children were), chimpanzees, go confronted with a problem that required the u se of a liquid tool in o rder to access a reward (peanut). Without any training, some chim panzees and human children found the solution in an insightful way. Several control conditions confirmed the goal directedness of chimpanzees’ behavior. None of the tested gorilla and orangutan subjects were successful. The next two studies ad dressed chimpanzees’ noti on of weight as a caus ally relevant object property. In STUDY II, chimpanzees were required to detect a bottle containing juice from five opaque bottles of equal shape and size. The bottl e of juice differed either by weight (causal property) or by color (a rbitrary pro perty) from the other bottles. It turn ed out that subjects’ searching behavior was strongl y influenced by the nature of the provided inform ation. Although chimpanzees readily inferred the bottle of juice from its causally relevan t property, they did not learn to use the arbitrary cue during the course of the experiment. STUDY III focused in more detail on the discrepancy be tween stimulus relations that are either arbitrarily or causally connected. C himpanzees had to infer the location of a reward (banana) by passively watching an external procedure. Tw o kinds of event sequences were presented: a causally inform ative sequence (derived from the physical effect of the reward) and a completely arbitrary sequence (d erived from an action u nrelated to the r eward). Again, chimpanzees perform ed m ore correctly when th e situation allowed for causal judg ments but failed to make useful inferences when the underlying logic was ar bitrary. Rem arkably, subjects appreciated the conceptual difference between these two experimental conditions that were perceptually very similar. Taking tog ether all of the current d ata, I s uggest that—s imilar to in hu mans—chimpanzees’ causal cognition is based not only on perceptual infor mation but also on structural abstraction about their physical environment. However, I speculate that humans might be the only species that is also able to conceptualize purely symbolic information.

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Acknowledgements Several factors m ust be seen as necessa ry (and hopefully sufficient) conditions for accomplishing this thesis: First of all I would like to expr ess my gratefulness for the privil ege of being a m ember of the Department of Developm ental and Com parative Psychology e mbedded in the very inspiring and fascinating research environm ent of t he Max P lanck Institut e of Evolutionary Anthropology in Leipzig. I would like to thank in particular Josep Call for his constant and patient guidance along the way and Michael To masello for his always open door and ear. Both of you exem plified what good science is a bout and why it is the mo st exciting thing to be doing. In addition, I am ve ry grateful to Prof. Van der Meer f or her open-m inded unbureaucratic manner and her scientific advice. I am particularly thankful to Rona Unrau and Nathan Pyne-Carter for their m eticulous proofreading and helpful comm ents. I thank as well Amanda Seed for sharing her crystal-clear th oughts with m e, and He inz Gretscher for his “Endnotethank Roger Mundry for his statisticalfalldienst”. Furtherm ore, I would like to support, Petra Jahn and Manuel Reinhartz for their assistance in all com puter-related things, and not to forget Henriette Zeidler, Anne tt W itzmann, and Jutta Katzer, who guided m e through every adm inistrative jungle. Many thanks also go to Raik Pieszek for transfor ming theoretical ideas in to f unctioning apparatu ses. For m any inter esting and stimulating discussions, I would like to thank Natacha Me ndes, Felix W arnecken, Keith Jens en, Julian e Kaminski, Juliane Bräuer, and Anna Albiach-Serrano. I would like to thank Brian Hare very m uch for bringing m e in touch with Uganda and supporting me with all his trem endous energy and boundless enthusiasm. Luckily I had two very enjoyable com panions during my stays in Africa, Alicia Melis and Esther Herrm ann. Also, I am extremely grateful to all who help ed with the data colle ction and coding, nam ely: Julia Cissewski, Martina Neum ann, Franziska Ze mke, Babette Voigt, Sandra Rolle, Mar len Kaufmann, and Marie Schäfer. I should not forget to mention the help of all the keepers at the Wolgang Köhler Primate Research Center. I would like to thank the management, the trustees and especially the staff of Nga mba Island Ch impanzee Sanctuary for their help and support, out of whom I would like to highlight Paulo Kibirige, Amos Okello, Stany Nyandwi, and Bruce Ainebyona. I also appreciate the Ugandan National Council for Science and Technology, the Uganda W ildlife Authority, an d the Orangutan Foundation International for allowing us to conduct our research in Uganda and Indonesia, respectively. Thanks to Claudio “Schisserrowski” Tennie for sharin g ideas (asked or unasked) and office space, an d for being a very good and reliable colleague and friend. Last but not least I would like to thank my parents, who evid ently caused my presence in th e first place and have always supported me in every respect. And thank you, Odette, for being there.

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List of original publications This dissertation is based on the following original research articles: STUDY I Hanus D., Mendes, N., Tennie, C., & Call, J. (subm itted). Com paring the pe rformances of apes and humans in the floating peanut task.Journal of Comparative Psychology. STUDY II Hanus, D., & Call, J. (subm itted). Contrastin g the use of causal and arbitrary cues in chimpanzees' problem s olving.nimal BehaviorJournal of Experimental Ps ychology: A Processes. STUDY III Hanus, D., & Call, J. (2 008). Chimpanzees infer the location of a reward based on th e effect of its weight. [Correspondence].Current Biology, 18(9), R370-R372. Addendum to STUDY III: Instead of using the original publ ished version, I incorporated an identical version in W ord of the manuscript. In addition, I included the suppl emental online data after the m ain document. Due to the special sty le guidelin es ofCurrent Biology, the general structure of this study differs from those of S TUDIES I and II. All e numerated references appear in the overall reference list.

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GENERAL INTRODUCTION “…no truth appears to me more evident, than that beasts are endow ed with thought and reason as well as men. The arguments are in this case so obvious, that they never escape the most stupid and ignorant.” David Hume Of the Reason of Ani mals (FromA Treatise o f Human Nature) Prologue When I recently ask ed the five -year-old daughter of a friendifshe had taken the last cookie from the tab le, she readily to ld mewhyshe had done so, referring to her trem endous hunger and her father’s perm ission. Interestingly, even though m y original que stion only sought an answer to w hether or not som ething had happe ned, it som ehow seemed evident to he r that I was actually interested in the reason behind or the cause for her behavior.W hat this little anecdote illustrates is an intriguing quality of human cognition. We humans obviously have a natural propensity to organize the physical (a nd psychological) environm ent around us into cause–effect structures. Such st ructuring allows us to understand the world in a way that goes beyond m ere probabilistic pred ictions and facilitates more accurate or app ropriate expectations. An exciting conundrum of com parative psychology is whether or not we share this cognitive peculiarity to some degree with other (closely related) species. Like m any other areas of scientif ic resear ch, th e inte rest in causality h as its roo ts in ancient philosophy. After the antiquity, David Hum e was one of the m ost influential thinkers to explore this issue. W hen he fam ously claimed that “cause an d effect” is a m an-made concept with purely perceptual repetitions underl ying the process of association (Hume , 1740/1739/1986), his radical stance challenged not only other phi losophers but also general common se nse. Many others have disputed hi s purely em piricist accou nt of causality (e.g., (Kant, 1787/1986; Mackie, 1980; Michotte, 1 963; Mill, 1843/1979), a nd a lively on-going debate continues to inspire scientific thinking. Before delineating the psychological relevance of the topic addressed by this thesis, I would like to cla rify explic itly what this work isnotabout. Given the em pirical character of this thesis, its pr imary intention canno t be a conc eptual clarification of the n ature of causation as such—in an ontological or epistem ological se nse. In contrast to m ost philosophical approaches and in order to ge nerate testable empirical hypot heses, a pragm atic notion of causality un derlies th is thesis. That is, a causal re lation b etween two events A a nd B is characterized by a spatial and tem poral con tingency in which A not only preced es B, but A

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