The Trouble with Twin Studies : A Reassessment of Twin Research in the Social and Behavioral Sciences

"The Trouble with Twin Studies questions popular genetic explanations of human behavioral differences based upon the existing body of twin research. Psychologist Jay Joseph outlines the fallacies of twin studies in the context of the ongoing decades-long failure to discover genes for human behavioral differences, including IQ, personality, and the major psychiatric disorders. This volume critically examines twin research, with a special emphasis on reared-apart twin studies, and incorporates new and updated perspectives, analyses, arguments, and evidence."-- Provided by publisher Cover 1 Title Page 4 Copyright Page 5 Dedication 6 Table of Contents 8 List of Illustrations 10 Preface 11 Acknowledgments 13 List of Abbreviations 14 PART I Studies of Reared-Apart Twins: Scientific Proof or Scientific Illusion? 16 1 Introduction 18 2 Studies of Reared-Apart Twins: Origins, Publications, and Scandal 32 3 Studies of Reared-Apart Twins:The Critics Respond 76 4 Studies of Reared-Apart Twins: Basic Assumptions and Potential Fallacies 90 5 The Minnesota Study of Twins Reared Apart I: Biases, Assumptions, and Other Problem Areas 117 6 The Minnesota Study of Twins Reared Apart II: IQ and Personality Studies 143 PART II Studies of Reared-Together Twins 166 7 The MZT–DZT Equal Environment Assumption: The Achilles Heel of the Classical Twin Method 168 8 Twin Research in Psychiatry 194 PART III Approaching a Post-Behavioral-Genetics Era? 220 9 Molecular Genetic Research: The Ultimate Test of Genetic Interpretations of Twin Studies 222 10 The Crumbling Pillars of Behavioral Genetics 237 11 A Human Genetics Parable 251 12 Summary and Conclusions 262 Appendix A: The Funding of MISTRA 268 Appendix B: A Little-Known Behavioral Genetic Adoption Study Whose Results Contrast with the MISTRA Personality Findings 274 Appendix C: List of Quotations from Twin Researchers and Others Invoking the “Twins Create Their Own Environment” Argument A in Defense of the MZT–DZT Equal Environment Assumption of the Twin Method: 1954–2014 282 Glossary 288 References 294 Index 323