Costly Signaling and Prey Choice: The Signaling Value of Hunted Game by Andrew Phillip Carson Bishop A Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Approved November 2019 by the Graduate Supervisory Committee: Kimberly Hill, Chair Robert Boyd Benjamin Trumble ARIZONA STATE UNIVERSITY December 2019 ABSTRACT For most of human history hunting has been the primary economic activity of men. Hunted animals are valued for their food energy and nutrients, however, hunting is associated with a high risk of failure. Additionally, large animals cannot be consumed entirely by the nuclear family, so much of the harvest may be shared to others. This has led some researchers to ask why men hunt large and difficult game. The “costly signaling” and “show-off” hypotheses propose that large prey are hunted because the difficulty of finding and killing them is a reliable costly signal of the phenotypic quality of the hunter. These hypotheses were tested using original interview data from Aché (hunter gatherer; n=52, age range 50-76, 46% female) and Tsimané (horticulturalist; n=40, age range 15-77, 45% female) informants. Ranking tasks and paired comparison tasks were used to determine the association between the costs of killing an animal and its value as a signal of hunter phenotypic quality for attracting mates and allies. Additional tasks compared individual large animals to groups of smaller animals to determine whether assessments of hunters’ phenotypes and preferred status were more impacted by the signal value of the species or by the weight and number of animals killed. Aché informants perceived hunters who killed larger or harder to kill animals as having greater provisioning ability, strength, fighting ability, and disease susceptibility, and preferred them as mates and allies. Tsimané informants held a similar preference for hunters who killed large game, but not for hunters targeting hard to kill species. When total biomass harvested was controlled, both populations considered harvesting more animals in a given time period to be a better signal of preferred phenotypes than killing a i single large and impressive species. Male and female informants both preferred hunters who consistently brought back small game over hunters who sometimes killed large animals and sometimes killed nothing. No evidence was found that hunters should forgo overall food return rates in order to signal phenotypic qualities by specializing on large game. Nutrient provisioning rather than costly phenotypic signaling was the strategy preferred by potential mates and allies. ii DEDICATION To my mom and dad, Phillip and Brenda Bishop. Throughout my life you have encouraged me to work hard and overcome obstacles. When I struggled, you were there for me. You taught me the value of learning and education. You inspired me with books about nature, culture, and science. You gave me opportunities to travel around the world from a young age, and in doing so, you exposed me to the diversity of human lifeways. My interest in Anthropology can be traced back directly to the unique experiences you provided for me throughout as a child. Most importantly, you have been a constant example of how to live a Godly life, and of how to leave the world better than you found it. Without your lifelong support, none of this work would have been possible. I dedicate this dissertation to you. iii ACKNOWLEDGEMENTS First, I would like to thank the Aché and Tsimané communities who generously agreed to allow me into their spaces. Thank you to the Aché people of Arroyo Bandera, Kue Tuvy, and Chupa Pou who spent hundreds of hours answering boring and repetitive questions about hunting and status, and who graciously allowed me to follow them on forest treks despite the fact that I am big, slow, an noisy. A special thank you to Germino Nuñez for your assistance as a translator, guide, mechanic, teacher, and friend. Thank you to the Tsimané communities who allowed me to live and work amongst you. Thank you to Asencio Lero Vie for your work as a guide, translator, and field assistant. Next, I would like to thank my professors, advisors, and colleagues at the School of Human Evolution and Social Change. Thank you to my chair, Kim Hill, for teaching me most of what I know about anthropology. I will value your friendship and the memories we have made over the years, both in Arizona and the Paraguay. Thank you to Rob Boyd for all that you have taught me about clear thinking, mathematical modeling, evolutionary theory, and for never dropping me during a rock-climbing session. Thank you to Ben Trumble for assisting me in professional development and for helping me design my research and plan my field work in Bolivia. Thank you to Michael Gurven for your input on this project. Thank you to Polly Wiessner, Curtis Marean, Joan Silk, Kaye Reed, Gary Schwartz, Amber Wutich, and Dan Hruschka for the contributions that each of you have made to my graduate education and professional development. In addition to faculty, I would like to thank Alex Danvers and Amanda McGrosky for your hard work and assistance in running statistical analyses for this project. iv Next, I would like to thank my fellow graduate students for their support, encouragement, and friendship over the past seven years. I would not have had the strength to complete my graduate studies without you. I would especially like to thank Adrian Chase, Charlotte Till, Chris and Heather Nafe, Jose Rosales-Chavez, and Gisela Velazques-Rosales, Maria Nieves Colón, Saul Alvarado, Joe Hackman, Brandice Evans, James Zerbe, and Julia Phelps. In addition to support I received at SHESC, I would also like to acknowledge Christopher Lynn of the University of Alabama for introducing me to evolutionary theory. Finally, I would like to thank the National Science Foundation Graduate Research Fellowship Program for supporting my research and studies (NSF GRFP grant number: 026257-001). I would like to thank the John Templeton Foundation for grants given to my advisor which were used in part to support this research. I would like to thank the School of Human Evolution and Social Change for funding me with a recruitment fellowship, as well as a graduate completion fellowship. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. (026257-001). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. v TABLE OF CONTENTS Page LIST OF TABLES ............................................................................................................ xii LIST OF FIGURES .......................................................................................................... xv CHAPTER 1 INTRODUCTION ............................................................................................... 1 Men’s Foraging Goals: Provisioning, Showing Off, and Costly Signaling .... 5 The Family Provisioning Hypothesis ....................................................... 5 The “Show-Off” Hypothesis .................................................................... 7 The Costly Signaling Hypothesis ........................................................... 11 Drawbacks of Costly Signaling Hypothesis for Studying Human Hunting Choices ............................................................................................ 14 Summary and Research Questions ................................................................ 16 2 LITERATURE REVIEW .................................................................................. 20 History and Background of Costly Signaling Theory ............................ 21 Grafen’s Costly Signaling Model ........................................................... 24 Critiques of Grafen’s Model ................................................................... 25 Ethnographic Evidence of Costly Signaling .................................................. 26 The Meriam Islanders ............................................................................. 28 Ifaluk Islanders ....................................................................................... 31 vi CHAPTER Page Kubo Hunter-Horticulturalists ................................................................ 32 Hadza Hunter-Gatherers ......................................................................... 33 Aché Hunter-Gatherers ........................................................................... 38 Martu Hunter Gatherers .......................................................................... 41 Tsimané Forager Horticulturalists .......................................................... 45 Ethnographic Summary ................................................................................. 47 Food Sharing: Kin Selection, Reciprocal Altruism, Indirect Reciprocity, Social Norms, and Tolerated Theft ........................................................ 50 Ethnographic Evidence of Kin Selection, Tolerated Theft, and Reciprocal Altruism .................................................................................................. 56 Kin Selection .......................................................................................... 57 Tolerated Theft ....................................................................................... 59 Reciprocity ............................................................................................