Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2012 The yS mbolic Mind: Apes, symbols, and the evolution of language Janni Pedersen Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Behavioral Disciplines and Activities Commons, Language Description and Documentation Commons, and the Reading and Language Commons Recommended Citation Pedersen, Janni, "The yS mbolic Mind: Apes, symbols, and the evolution of language" (2012). Graduate Theses and Dissertations. 12430. https://lib.dr.iastate.edu/etd/12430 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. The symbolic mind: Apes, symbols, and the evolution of language by Janni Pedersen A dissertation submitted to the graduate faculty in partial fulfillment of the requirement for the degree of DOCTOR OF PHILOSOPHY Major: Ecology and Evolutionary Biology Program of Study Committee: Jill D. Pruetz Major Professor Anne Bronokowski Rolf Koford Bonnie Bowen Mack Shelley William M. Fields Iowa State University Ames Iowa 2012 ii Table of Contents Acknowledgements ................................................................................................................................ v Chapter 1. Introduction ......................................................................................................................... 1 The question of animal thought and language .................................................................................. 1 An interdisciplinary endeavor ............................................................................................................ 3 Dissertation organization ................................................................................................................... 6 The study subjects .............................................................................................................................. 7 Ape language research ..................................................................................................................... 11 Bonobos ............................................................................................................................................ 14 The thought and language debate ................................................................................................... 16 The Greek Heritage ....................................................................................................................... 16 Empiricism vs. Rationalism ........................................................................................................... 17 Chomsky and modern linguistics .................................................................................................. 18 Synthesis and new perspectives ................................................................................................... 22 References ........................................................................................................................................ 24 Appendix 1: Bonobo subjects' biographies. ..................................................................................... 28 Appendix 2: Schematics of bonobo laboratory ................................................................................ 30 Chapter 2. Taking Apes Seriously: A reply to the debate between Tomasello and Boesch ................ 31 Abstract ............................................................................................................................................ 31 Introduction ...................................................................................................................................... 31 Field or Captive Primate Studies? .................................................................................................... 32 Taking Development Seriously ..................................................................................................... 32 The Validity of Captive Studies ..................................................................................................... 35 A New Look at the Debate ................................................................................................................ 35 The Natural Environment ............................................................................................................. 35 Determinism and Speciesism ....................................................................................................... 38 New Directions ................................................................................................................................. 41 Development and Evolution ......................................................................................................... 42 Symbolic Communication and Cognition ..................................................................................... 44 Conclusion ........................................................................................................................................ 46 References ........................................................................................................................................ 48 Chapter 3. The Effect of Symbols on Categorization in Bonobos ......................................................... 51 Abstract ............................................................................................................................................ 51 Introduction ...................................................................................................................................... 51 iii Methods ........................................................................................................................................... 55 Subjects ........................................................................................................................................ 55 Procedure ..................................................................................................................................... 56 Training Phase .............................................................................................................................. 58 Assessing Symbolic Competencies ............................................................................................... 59 Categorical Matching Study.......................................................................................................... 61 Ethical Note ...................................................................................................................................... 64 Results .............................................................................................................................................. 64 Symbolic Competencies ............................................................................................................... 64 Identity Matching ......................................................................................................................... 65 Categorical matching .................................................................................................................... 66 Discussion ......................................................................................................................................... 69 The influence of symbols on thought ........................................................................................... 69 The body as semantic template ................................................................................................... 71 Levels of categories ...................................................................................................................... 72 Evolution of language ................................................................................................................... 73 Conclusion ........................................................................................................................................ 74 Acknowledgements .......................................................................................................................... 75 References ........................................................................................................................................ 76 Appendix 1 ........................................................................................................................................ 79 Food items ........................................................................................................................................ 79 Chapter 4. Auditory or visual arbitrary association: is there a difference in the learning abilities of symbolically competent and non-symbolically competent apes? ....................................................... 85 Abstract ............................................................................................................................................ 85 Introduction ...................................................................................................................................... 85 Methods