NORTH CAROLINA LAW REVIEW Volume 75 | Number 4 Article 2 4-1-1997 Evolutionary Analysis in Law: An Introduction and Application to Child Abuse Owen D. Jones Follow this and additional works at: http://scholarship.law.unc.edu/nclr Part of the Law Commons Recommended Citation Owen D. Jones, Evolutionary Analysis in Law: An Introduction and Application to Child Abuse, 75 N.C. L. Rev. 1117 (1997). Available at: http://scholarship.law.unc.edu/nclr/vol75/iss4/2 This Article is brought to you for free and open access by Carolina Law Scholarship Repository. It has been accepted for inclusion in North Carolina Law Review by an authorized administrator of Carolina Law Scholarship Repository. For more information, please contact [email protected]. EVOLUTIONARY ANALYSIS IN LAW: AN INTRODUCTION AND APPLICATION TO CHILD ABUSE OWEN D. JONEs* For contemporary biologists, behavior-like physical form- evolves. Although evolutionaryprocesses do not dictate behavior in any inflexible sense, they nonetheless contribute significantly to the prevalence of various behavioralpredispositions that, in turn, tend to yield observable patterns of behavior within every known species. In this Article, Professor Owen D. Jones carefully explores the implications for law of evolved behavioral predispositions in humans, urging both caution and optimism. He first provides an introduction to law-relevant evolutionary biology, assuming no prior knowledge in the subject. He then proposes a model for conducting "evolutionary analysis in law"--by which legal thinkers can locate, assess, and use knowledge about evolutionary influences on human behavior to further the pursuit of many existing social and legal goals. The Article illustrates the operation of that method by showing how it could aid ongoing efforts to understand and curb child abuse. Throughout, Professor Jones emphasizes how the evolutionary perspective on human behavior will typically and usefully supplement, rather than supplant, prevailing notions of the many influences on behavior and the complex interactionsamong them. * Associate Professor of Law, Arizona State University College of Law; Research Fellow, Gruter Institute for Law & Behavioral Research; B.A., Amherst College; J.D., Yale Law School. I have benefited greatly from the generous comments and advice, on various aspects of this work, from biologists John Alcock, Timothy Goldsmith, Robert Trivers, and William Zimmerman; primatologist and evolutionary psychiatrist Michael McGuire; primatologists Frans de Waal and Sarah Hrdy; and evolutionary psychologist Martin Daly. I am also grateful for the thoughtful comments, on earlier drafts of this Article, from Kingsley Browne, Ira Ellman, Steven Goldberg, Lydia Jones, David Kader, Dennis Karjala, David Kaye, Gary Lowenthal, John McGinnis, Roger Masters, Jonathan Rose, Daniel Strouse, Cynthia Ward, Jim Weinstein, and Larry Winer, and for the sus- tained efforts of Margaret Gruter to foster interdisciplinary cooperation on these subjects. The views expressed here, of course, may or may not be shared by anyone just mentioned. Jacqueline Ganier provided most able research assistance, to which Kurt Luther, Pamela Winston, and James Saul also valuably contributed. The author acknowl- edges the generous research support provided by the Arizona State University College of Law. Please direct correspondence to [email protected]. 1118 NORTH CAROLINA LAW REVIEW [Vol. 75 INTRODUCTION .................................................................................... 1120 I. A PRIMER IN LAW-RELEVANT EVOLUTIONARY BIOLOGY ....................................................................................... 1126 A. PreparatoryRemarks: Law and Biology on Causation................................................................................ 1127 B. The Evolutionary Perspective: On the Making of A ncestors................................................................................ 1129 1. The Duration of the Game: The Clock of Evolution ......................................................................... 1129 2. The Objective of the Game: Persistence of Existence ......................................................................... 1132 a. Getting Ahead: Reproductive Success ................. 1132 b. Keeping Score: Inclusive Fitness ........................... 1133 3. The Ground Rule for the Game: Natural Selection ...........................................................................1135 4. The Strategies for the Game: Reproductive Strategies ......................................................................... 1141 a. Parental Investment ................................................. 1141 b. Sexual Reproduction ............................................... 1142 c. Sexual Selection: A Special Rule for a Special Strategy ...................................................................... 1144 d. Condition-Dependent Strategies ........................... 1146 5. The Strategies in Tension: On Conflict, Cooperation, and Deception ......................................... 1146 a. Conflict ...................................................................... 1147 b. Cooperation .............................................................. 1149 c. Deception and Self-Deception ............................... 1151 6. Homo sapiens sapiens ....................................................1152 C. Closing Remarks: Some Points to Take Away .................. 1155 II. EVOLUTIONARY ANALYSIS IN LAW: A MODEL, AND ITS APPLICATION TO CHILD A BU SE ...........................................................................................1157 A. The Identification Stage ........................................................ 1160 1. What Is the Legal Goal? ............................. ................... 1160 2. Will Evolutionary Analysis Further Pursuit of That Goal? ....................................................................... 1163 a. What Are the Prevailing Theories? . 1164 b. Is the Failure to Achieve the Goal Solely Attributable to Inadequate Implementation of Adequate Theories? ............................ .................... 1166 c. Are the Prevailing Theories Already Informed by the Influence of Natural Selection on 1997] EVOLUTIONARY ANALYSIS IN LAW 1119 B ehavior? ....................................... ........................... 1167 d. How Greatly Might the Behavior in Question Have Affected the Reproductive Success of Our Ancestors? ........................................................ 1169 3. Summary ..........................................................................1170 B. The Information Stage .......................................................... 1170 1. What Are the Relevant Evolutionary Theories and Predictions? ..................................... ......................... 1171 a. The Evolutionary Theories: An Example ............ 1172 b. The Predictions of Evolutionary Theories: An Exam ple .................................................................... 1181 2. What Empirical Evidence Bears on Those Predictions? ......................................... ............................ 1184 a. Infanticide in Non-Primates: The Evidence ........ 1185 b. Infanticide in Non-Human Primates: The Evidence ............................................................ 1189 c. Infanticide in Humans: The Evidence .................. 1192 (1) Child-Killingin Homo sapiens sapiens: An Overview ...........................................................1193 (2) Representative Predictions.............................. 1200 3. How Does the Evidence Fit the Predictions? ........ ..... 1208 4. Do the Theories Apply to Humans? ................. ........... 1211 5. Should the Theories Be Considered in Legal Analysis and Policy-making? ........................ ................ 1214 6. Summary ..........................................................................1216 C. The IntegrationStage ............................................................ 1216 1. Where Do Prevailing and Evolutionary Theories Conflict? .................................. ........................ 1217 a. Conflicts Between Theoretical Substructures ...... 1217 (1) Differences in Levels of Analysis ................... 1217 (2) Differences in Basic Assumptions .................. 1219 b. Conflicts Between Predictions ................................ 1220 2. How May Non-Conflicting Elements Be Integrated? ......................................... ............................. 1222 3. Sum m ary ..........................................................................1225 D. The Application Stage ........................................................... 1226 1. How Can Evolutionary Analysis Help To Refine Behavioral Models? .......................... ................. 1227 a. How It Can Help ...................................................... 1227 b. Aren't Statistics Alone Enough? ................ ........... 1229 c. Won't Evolutionary Analysis Often Simply Confirm Common Intuitions? ................... ............. 1231 1120 NORTH CAROLINA LAW REVIEW [Vol. 75 2. How Can Evolutionary Analysis Help To Generate New Legal Strategies? .................... .............. 1232 3. How Can Evolutionary Analysis Help To Improve Cost-Benefit Analyses? .................... .............. 1236 4. How Can Evolutionary Analysis Help To Reveal Promising Directions for Future R esearch? ........................................................................1240 III. CONCLUSION ...............................................................................