Table of Contents

Preface xi Chapter 1: A Cooperative Species 1 Chapter 2: The Evolution of Altruism in Humans 8 2.1 Preferences, Beliefs, and Constraints 9 2.2 Social Preferences and Social Dilemmas 10 2.3 Genes, Culture, Groups, and Institutions 13 2.4 Preview 18 Chapter 3: Social Preferences 19 3.1 Strong Reciprocity Is Common 20 3.2 Free-Riders Undermine Cooperation 22 3.3 Altruistic Punishment Sustains Cooperation 24 3.4 Effective Punishment Depends on Legitimacy 26 3.5 Purely Symbolic Punishment Is Effective 29 3.6 People Punish Those Who Hurt Others 31 3.7 Social Preferences Are Not Irrational 32 3.8 Culture and InstitutionsMatter 33 3.9 Behavior Is Conditioned on Group Membership 35 3.10 People Enjoy Cooperating and Punishing Free-Riders 38 3.11 Social Preferences in Laboratory and Natural Settings 39 3.12 Competing Explanations 42 Chapter 4: The Sociobiology of Human Cooperation 46 4.1 Inclusive Fitness and Human Cooperation 48 4.2 Modeling Multi-level Selection 52 4.3 EquilibriumSelection 57 4.4 Reciprocal Altruism 59 4.5 Reciprocal Altruism in Large Groups 63 4.6 Reputation: Indirect Reciprocity 68 4.7 Altruism as a Signal of Quality 71 4.8 Positive Assortment 72 4.9 Mechanisms and Motives 75 Chapter 5: Cooperative Homo economicus 79 5.1 Folk Theorems and Evolutionary Dynamics 80 5.2 The Folk Theorem with Imperfect Public Information 83 5.3 The Folk Theorem with Private Information 86 5.4 Evolutionarily Irrelevant Equilibria 87 5.5 Social Norms and Correlated Equilibria 89 5.6 The Missing Choreographer 90 Chapter 6: Ancestral Human Society 93 6.1 Cosmopolitan Ancestors 95 6.2 Genetic Evidence 99 6.3 PrehistoricWarfare 102 6.4 The Foundations of Social Order 106 6.5 The Crucible of Cooperation 110 Chapter 7: The Coevolution of Institutions and Behaviors 111 7.1 Selective Extinction 115 7.2 Reproductive Leveling 117 7.3 Genetic Differentiation between Groups 120 7.4 Deme Extinction and the Evolution of Altruism 121 7.5 The Australian Laboratory 123 7.6 The Coevolution of Institutions and Altruism 124 7.7 Simulating Gene-Culture Coevolution 126 7.8 Levelers and Warriors 130 Chapter 8: Parochialism, Altruism, andWar 133 8.1 Parochial Altruism and War 135 8.2 The Emergence of Parochial Altruism and War 138 8.3 Simulated and Experimental Parochial Altruism 142 8.4 The Legacy of a Past "Red in Tooth and Claw" 146 Chapter 9: The Evolution of Strong Reciprocity 148 9.1 Coordinated Punishment 150 9.2 Altruistic Punishment in a Realistic Demography 156 9.3 The Emergence of Strong Reciprocity 159 9.4 Why Coordinated Punishment Succeeds 163 9.5 A Decentralized Social Order 164 Chapter 10: Socialization 167 10.1 Cultural Transmission 168 10.2 Socialization and the Survival of Fitness-Reducing Norms 171 10.3 Genes, Culture, and the Internalization of Norms 173 10.4 The Internalized Norm as Hitchhiker 176 10.5 The Gene-Culture Coevolution of a Fitness-Reducing Norm 179 10.6 How Can Internalized Norms Be Altruistic? 180 10.7 The Programmable Brain 183 11 Social Emotions 186 11.1 Reciprocity, Shame, and Punishment 188 11.2 The Evolution of Social Emotions 191 11.3 The "Great Captains of Our Lives" 192 12 Conclusion: Human Cooperation and Its Evolution 195 12.1 The Origins of Human Cooperation 196 12.2 The Future of Cooperation 199 Appendix 201 A1 Altruism Defined 201 A2 Agent-Based Models 202 A3 Game Theory 207 A4 Dynamical Systems 209 A5 The Replicator Dynamic 212 A6 Continuation Probability and Time Discount Factor 213 A7 Alternatives to the Standing Model 214 A8 The Prisoners Dilemma with Public and Private Signals 215 A9 Student and Nonstudent Experimental Subjects 217 A10 The Price Equation 218 A11 Weak Multi-level Selection 222 A12 Cooperation and Punishment with Quorum Sensing 223 References 225 Subject Index 251 Author Index 255

About the Author

Samuel Bowles heads the Behavioral Sciences Program at the Santa Fe Institute and teaches economics at the University of Siena. Herbert Gintis holds faculty positions at the Santa Fe Institute, Central European University, and the University of Siena.

Reviews

"The achievement of Bowles and Gintis is to have put together from the many disparate sources of evidence a story as plausible as any we're likely to get in the present state of behavioural sciences of how human beings came to be as co-operative as they are."--W.G. Runciman, London Review of Books "In A Cooperative Species, economists Samuel Bowles and Herbert Gintis update their ideas on the evolutionary origins of altruism. Containing new data and analysis, their book is a sustained and detailed argument for how genes and culture have together shaped our ability to cooperate... By presenting clear models that are tied tightly to empirically derived parameters, Bowles and Gintis encourage much-needed debate on the origins of human cooperation."--Peter Richerson, Nature "An outstanding book that presents an important contribution and quite simply raises the scientific standard associated with the difficult and contentious problem of how human altruism evolved."--Charles Efferson, Economic Journal "A Cooperative Species: Human Reciprocity and Its Evolution states a clearly articulated gene-culture coevolution explanation for why we are a cooperative species. It is a read that will stretch readers' minds a bit, and I think it is an eminently valuable read... I await with eagerness the next time Bowles and Gintis are out cooperating again."--Jonathan D. Springer, PsycCRITIQUES "[T]he authors' systematic and mathematical approach will appeal to any reader seriously interested in learning about alternative theories of adaptive altruism, and their treatment of cultural inheritance using population-genetic models is first-rate. Although this book will by no means settle the debate surrounding the evolutionary origin of altruism, it is a worthy addition and is well worth reading."--P. William Hughes, Journal of Economic Issues "Bowles and Gintis are clearly not short of ideas. The attention they draw to the role of conflict and coordinated punishment in the evolution of our cooperative and reciprocal species makes the book very much worth reading. Their focus on the evolution of human nature also paints a much richer picture of our behavior than traditional economics tends to do."--Journal of Economic Literature "Bowles and Gintis are not the first to claim that competition, conflict, and war between human groups is the foundation of cooperation and of society. However, their integration of this insight into evolutionary game theory stands to increase the accessibility of this powerful idea to a large number of scholars working in a dominant theoretical perspective that spans the social and biological sciences. This is one reason why I recommend their new book A Cooperative Species: Human Reciprocity and Its Evolution."--Noah Mark, Journal of Artificial Societies and Social Simulation "This book makes a strong case for returning as a discipline to this vexed theme. I can only hope we do so with the analytical ingenuity and empirical humility that Bowles and Gintis display."--Jacob G. Foster, American Journal of Sociology