BEHAVIORAL ECOLOGY OF TOBACCO AND CANNABIS USE AMONG AKA FORAGERS OF THE CONGO BASIN By CASEY JORDAN ROULETTE A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY WASHINGTON STATE UNIVERSITY Department of Anthropology MAY 2015 © Copyright by CASEY JORDAN ROULETTE, 2015 All Rights Reserved © Copyright by CASEY JORDAN ROULETTE, 2015 All Rights Reserved To the Faculty of Washington State University: The members of the Committee appointed to examine the dissertation of CASEY JORDAN ROULETTE find it satisfactory and recommend that it be accepted. ___________________________________ Edward H. Hagen, Ph.D., Chair ___________________________________ Barry S. Hewlett, Ph.D. ___________________________________ Robert J. Quinlan, Ph.D. ii ACKNOWLEDGEMENT I would like to thank my committee for their guidance, expertise, patience, and trust. These are: Edward Hagen, my PhD chair, who introduced me to evolutionary approaches to substance use and provided countless hours of mentoring and advice; Barry Hewlett, who opened my mind to anthropology and who introduced me to the Aka; Rob Quinlan, who introduced me to field work and urged me to apply to the evolutionary anthropology program. None of this would have been possible without the Aka, who graciously agreed to participate, who found humor in the questions and tasks asked of them, and who provided assistance in the field. It has truly been a great experience working and spending time with them. I would also like to thank the people of the villages of Bagandou, Kenga, and Moboma, CAR, for their hospitality, especially my research assistants, Mesmin Dopeningue, the late Nicaise Molende, Alaine Guy Kolet, Aubin Mongosso, and Eduard Mboula, without who’s help the project never would have been completed. There are several professors, colleagues, and associates who helped along the way. These include Dr’s Marsha Quinlan, Bonnie Hewlett, Nicole Hess, Brian Kemp, Colin Grier, Courtney Meehan, Cara Monroe, and Roger Sullivan, who provided additional support and guidance. Also, Haley Mann, Jennifer Roulette, Mark Remiker, Mirdad Kazanji and the rest of the staff at Institute Pasteur in Bangui, all of whom helped in data collection and/or analyses. Thanks also to Elsevier and John Wiley and Sons for permission to reprint, as well as to the anonymous reviewers for their comments and suggestions. iii Finally, I would like to thank my family. These include my parents--Marie and Fred Snaza, Scott and Debora Roulette, and Steve and Ellen Wilcox—as well as my sister, Saidi Roulette, for believing in and never giving up on me, and for all of their support. My wonderful daughter, Emma, who provided me with a new focus and perspective that helped propel me through the finish line. And most importantly, my amazing wife and colleague, Jennifer Ellen Wilcox Roulette, with whom I shared this journey and whose love and support made it all possible. Thank you all! iv BEHAVIORAL ECOLOGY OF TOBACCO AND CANNABIS USE AMONG AKA FORAGERS OF THE CONGO BASIN Abstract by Casey Jordan Roulette, Ph.D. Washington State University May 2015 Chair: Edward H.Hagen Little is known about substance use among extant hunting-gathering populations. I therefore conducted one of the first biocultural, and biomarker validated, studies of tobacco and cannabis among the Aka foragers of the Congo Basin. Because tobacco and cannabis contain anthelmintic compounds, and because the Aka suffer from high rates of helminthiasis, I also tested a hypothesis that recreational use of neurotoxic plants helps defend against parasites. Self- and peer-reports of tobacco and cannabis were collected from all Aka residing in the study area (n=379). Detailed questions about substance use were asked among a subset of these. Because female use was low, I restricted saliva, urine and stool sample collections to men. Saliva samples were assayed for cotinine, a nicotine metabolite; urine samples were assayed for THCA, a metabolite of THC; a subsample was genotyped for the CYP2A6 enzyme, which metabolizes nicotine. Stool samples were assayed for intestinal helminth eggs as an index of worm burden. Aka men pay more for tobacco, yet have a higher smoking prevalence (95%) than men in most other populations, whereas Aka women have a low prevalence. Aka thus have one of the largest known gender differences in smoking. Tobacco is widely shared, and might play a central role in this defining aspect of Aka culture. Significant negative correlations between cotinine and worm burden and THCA and worm burden were found. Treating helminths with a commercial anthelmintic reduced cotinine concentration two weeks later, compared to placebo controls. Significant negative rank correlations were found between year 1 cotinine concentrations and reinfection by year 2 and between year 2 THCA v concentrations and reinfection. Finally, younger and older participants with slow nicotine-metabolizing alleles had lower worm burdens compared to those with extensive metabolizing alleles. Tobacco advertising cannot easily explain the high prevalence of smoking among Aka men, nor can socioeconomic disparities, proscriptions, or the addictiveness of nicotine easily explain the low prevalence among Aka women. Aka smoking might be better explained by internal, rather than external, cultural and political-economic factors. In addition, these results provide the first support for the hypothesis that substance use helps defend against parasites. vi TABLE OF CONTENTS Page ACKNOWLEDGMENTS ....................................................................................................................... iii ABSTRACT .............................................................................................................................................v LIST OF TABLES ..................................................................................................................................ix LIST OF FIGURES .................................................................................................................................x 1. INTRODUCTION ............................................................................................................................... 1 2. PUZZLE OF HIGH MALE TOBACCO USE, AND LOW FEMALE USE, AMONG CONGO BASIN FORAGERS: IMPLICATIONS FOR ANTHROPOLOGICAL THEORIES OF DRUG USE AND PUBLIC HEALTH .......................................................................................................................... 7 ABSTRACT ........................................................................................................................................... 8 INTRODUCTION .................................................................................................................................... 9 METHODS .......................................................................................................................................... 16 RESULTS ........................................................................................................................................... 18 DISCUSSION ...................................................................................................................................... 32 CONCLUSIONS ................................................................................................................................... 40 ACKNOWLEDGEMENTS ....................................................................................................................... 41 REFERENCES .................................................................................................................................... 43 3. TOBACCO USE VS. HELMINTHS IN CONGO BASIN HUNTER-GATHERERS: SELF- MEDICATION IN HUMANS? Roulette CJ, Mann H, Kemp BM, Remiker M, Roulette JW, Hewlett BS, et al. (2014). Evolution and Human Behavior, 35(5):397-407. http://dx.doi.org/10.1016/j.evolhumbehav.2014.05.005........................................................................ 50 ABSTRACT ......................................................................................................................................... 51 INTRODUCTION .................................................................................................................................. 52 STUDY .............................................................................................................................................. 58 MATERIALS AND METHODS ................................................................................................................. 63 vii RESULTS ........................................................................................................................................... 68 DISCUSSION AND LIMITATIONS ............................................................................................................ 74 ACKNOWLEDGEMENTS ....................................................................................................................... 81 REFERENCES .................................................................................................................................... 82 LIST OF TABLES .................................................................................................................................. 96 FIGURE LEGENDS ............................................................................................................................... 98 FIGURES ........................................................................................................................................