EVOLUTION AND RELIGION: THEORY, DEFINITIONS, AND THE NATURAL SELECTION OF RELIGIOUS BEHAVIOR A Thesis presented to the Faculty of the Graduate School at the University of Missouri In Partial Fulfillment of the Requirements for the Degree Masters of Arts by RYAN M. ELLSWORTH Dr. Craig T. Palmer, Thesis Committee Chair MAY 2009 The undersigned, appointed by the dean of the Graduate School, have examined the thesis entitled EVOLUTION AND RELIGION: THEORY, DEFINITIONS, AND THE NATURAL SELECTION OF RELIGIOUS BEHAVIOR Presented by Ryan M. Ellsworth, a candidate for the degree of Master of Arts, Anthropology, and hereby certify that, in their opinion, it is worthy of acceptance. Professor Craig T. Palmer Professor Mark. V. Flinn Professor David C. Geary ACKNOWLEDGEMENTS I would first and foremost like to thank my mentor and intellectual ancestor Dr. Craig T. Palmer, whose teachings, discussions, and patient instruction on both evolutionary theory and the anthropological study of religious behavior have greatly inspired much of the content in the present work. An additional debt of gratitude is owed to Professor Palmer for his collaborative efforts in the formulation, conduction, and analyses of the studies presented in chapter 4. I also thank Dr. Mark Flinn and Dr. David Geary whose insightful lessons on evolution and human behavior have had a strong influence on my graduate education. I also extend a grateful and appreciative acknowledgement to the entire faculty, staff, and graduate student body of the Department of Anthropology at the University of Missouri for their support, ideas, and tutelage over the past three years. ii TABLE OF CONTENTS ACKNOWLEDGEMENTS……………………………………………………...ii LIST OF TABLES……………………………………………………………....v INTRODUCTION…………………………………………………………….……………1 CHAPTERS 1: A Review of Some Recent Evolutionary Approaches to Religion………………………………………………………………………..3 Evolutionary Cognitive Psychological Approaches to Religion; Behavioral Ecological Approaches to Religion. 2: Adaptation-Byproduct Debate in the Evolutionary Study of Religion…..….23 Religion as Evolutionary By-product; Religion as Evolutionary Adaptation. 3: Defining Religion….………………………………………………………...33 The Problem with “Belief” in the Definition of Religion; Further Issues in Defining Religion; A Proposed Definition of Religion. 4: Testing the Definition of Religion as The Communicated Acceptance of Supernatural Claims…………………………………….…...47 Survey #1: Testing the Hypothesis that Supernatural Claims are Judged “Religious”; Predictions; Method and Procedure of Survey #1; Results of Survey #1; Survey #2: Testing Three Hypotheses Regarding Cross-Cultural Criteria for the Identification of Religious Behavior; Hypothesis Number One: LSV; Hypothesis Number Two: Emotive Ritual; Hypothesis Number Three: Communicated Acceptance of Supernatural Claims; Method and Procedure of Survey #2; Responses to the Slides With Only Visual Images; Results; Responses to the Slides With the Addition of Statements Indicating the Communicated Acceptance of a Supernatural Claim or Skepticism of a Supernatural Claim; Results; Discussion. 5: Religious Behavior as Adaptation: Natural Selection, Traditions and Evolutionary Success…………………………………………………....64 The Evolution of Learning; Individual Learning; Social Learning; Traditions in Evolutionary Perspective; Traditional Religious Behavior: Ancestor Worship; The Evolutionary Significance of Ancestor Worship Traditions; Kin Selection or iii Descendant-Leaving Strategy?; Religious Behavior and Evolutionary Success; Is Religious Behavior an Adaptation?; Religious Behavior is an Adaptation. 6: Conclusion…………………………………………………………………..99 REFERENCES………………………………………………………………103 iv LIST OF TABLES Table Page 1. Table showing comparison of total ratings for slides with images only, slides with type indicating that natural claims were associated with the behavior in the image, and slides with type indicating that supernatural claims were associated with the behavior in the image………………………………………………………………………………...50 2. Table showing comparison of total ratings for slides showing control images and slides showing LSV images………………………………………………………….56 3. Table showing comparison of total ratings for slides showing control images and Slides showing emotive ritual images………………………………………………..56 4. Table showing comparison of total ratings for slides showing control images without statements indicating the communicated acceptance of supernatural claims (CASNC) and slides showing control images with statements indicating the communicated acceptance of supernatural claims…………………………………………………...58 5. Table showing comparison of total ratings for slides showing LSV and emotive ritual images without statements indicating the communicated acceptance of supernatural claims (CASNC) and slides showing LSV and emotive ritual images with statements indicating the communicated acceptance of supernatural claims…………………..58 6. Total scores (control, LSV, and Emotive Ritual) for slides with the communicated acceptance of supernatural claims compared with total scores for slides with skepticism of supernatural claims…………………………………………………...59 7. Table showing comparison of total ratings for slides with images only, slides with type indicating that natural claims were associated with the behavior in the image, and slides with type indicating that supernatural claims were associated with the behavior in the image (from Survey #1)…………………………………………….60 v Introduction Beginning in the late 1960’s, revolutionary breakthroughs within evolutionary biological theory led to great advances in the study and understanding of animal behavior. It was inevitable that these new ideas that contributed so much insight into the evolution of behavior would soon be applied to our own species. Today, the study of humanity from a Darwinian perspective addresses nearly every aspect of our lives. One topic that has been increasingly investigated over the past twenty years by evolution-minded researchers is that of religion. This wholly unique human attribute is perhaps one of the most challenging issues facing students of evolution and human behavior. Natural selection punishes those organisms not in touch with reality, yet everywhere in the world, in every culture, we find a pre-occupation with an unobservable realm of supernatural beings, powers, and forces. What is it about the natural history of our species that has led to the universal presence of religion? Was religion favored by natural selection? Is it merely a side effect of the way our minds have evolved? More importantly, what is religion, anyway? None of the important evolutionary questions about religion can be satisfactorily answered without first reaching agreement on a definition. This thesis attempts to advance evolutionary understanding of religion by identifying what is meant by the word religion—that is, what behaviors should and should not be considered religious, and exploring the implications this definition has for explaining the evolution of this behavior. In the first chapter, a brief and impartial summary of recent theory and research into religion from the perspectives of evolutionary cognitive psychology and behavioral ecology is presented. This is intended to orient the reader to the 1 contemporary approaches and to pave the way for critical thinking about these approaches in the chapters that follow. Chapter 2 discusses one of the prominent points of contention in the evolutionary study of religion; this is the issue of whether or not religion is an adaptation directly favored by natural selection in human history, or if religion is a by-product of other traits that were not favored for their effects in producing religion. The implications of how religion is defined for how it is explained are also introduced in chapter 2, as well as a discussion of what is required to build a valid argument for religion as an adaptation. In Chapter 3, focus is shifted from the topic of explanation to that of definition. Here, critical discussion of what is and is not appropriate criteria for an accurate definition of religion is presented, existing definitions are scrutinized, and in their place, an alternative definition is proposed. Chapter 4 presents the results of two studies formulated to test the definition of religion posited in chapter 3. Finally, Chapter 5 lays out an explanation of the evolution of religion as a traditional behavior that was directly favored by natural selection for its effects on the descendant-leaving success of ancestral humans. 2 Chapter 1: A Review of Some Recent Evolutionary Approaches to Religion The past two decades have witnessed a resurgence of scientific interest in the study of religion. At the forefront of this revitalization have been scholars employing various approaches rooted in biological theory. Although all of these approaches share a common core metatheoretical foundation, they also differ in significant ways. Researchers working in cognitive psychology, cultural anthropology, behavioral ecology, neuroscience, and other fields approach the topic of religion using different research methods, theoretical frameworks, and paradigmatic assumptions. The result is a rather heterogeneous body of theory and research concerning the evolutionary study of religion. In this chapter I review some of the more prominent and influential evolutionary approaches to religion, focusing on only a narrow sample of theory, studies, and authors. This scope should allow for a greater understanding of the central key topics than