مسئله‌ی مطالعات دوقلویی ۲۰۱۴
The Trouble with Twin Studies 2014

1. Cover Page

2. Half Title Page

3. Title Page

4. Copyright Page

5. Dedication

6. Contents

7. List of Illustrations

8. Preface

9. Acknowledgements

10. List of Abbreviations

11. I Studies of Reared-Apart Twins Scientific Proof or Scientific Illusion?

1 Introduction

13. The Historical Background

14. Human Behavioral Genetics

15. Primary Methods of Behavioral Genetics and Psychiatric Genetics

16. Family Studies

17. The Twin Method (Twins Reared Together)

18. Adoption Studies

19. Reared-Apart Twin Studies

20. Molecular Genetic Research

21. Notes

2 Studies of Reared-Apart Twins Origins, publications, and scandal

23. The First Studied Reared-Apart Monozygotic Twin Pair

24. The Classical Reared-Apart Twin Studies

25. Newman, Freeman, and Holzinger, 1937

26. Sampling bias

27. Were these really “reared-apart” MZ twins?

28. Conclusion

29. Shields, 1962

30. Sample, goals, and biases

31. Results and Shields' interpretations

32. Degree of separation

33. Conclusion

34. Juel-Nielsen, 1965

35. Overview

36. Assumptions

37. Lack of a control group

38. Degree of contact and environmental similarity

39. Other sources of bias

40. Conclusion

41. The Cyril Burt Scandal

42. The Controversy Surrounding Arthur Jensen

43. The Minnesota Study of Twins Reared Apart

44. Selectively Reported MZA Pairs

45. Other TRA Studies

46. Conclusions

47. Notes

3 Studies of Reared-Apart Twins The Critics Respond

49. Leon Kamin, 1974

50. Howard Taylor, 1980

51. Susan Farber, 1981

52. Leon Kamin, in Eysenck vs. Kamin, 1981

53. Richard Rose, 1982

54. Richard Lewontin, Steven Rose, and Leon Kamin, 1984

55. Ken Richardson, 1998

56. Leon Kamin and Arthur Goldberger, 2002

57. My Previous Analyses

58. Conclusions

59. Notes

4 Studies of Reared-Apart Twins Basic Assumptions and Potential Fallacies

61. Psychometrics

62. Heritability

63. Heritability ≠ Inherited

64. Variation ≠ Cause

65. Heritability and Psychiatric Disorders

66. Some Leading Behavioral Geneticists Now Recognize that Heritability Estimates “Are Not Very Important”

67. Model Fitting

68. An “Important First Step”

69. Questionable Assumptions

70. Circular Reasoning

71. Random Assignment

72. IQ Tests

73. Criticism of IQ Testing

74. IQ Score Differences Based on Accepted and Rejected Assumptions

75. “Personality” and Personality Tests

76. Personality Tests Rejected by Leading Personnel Psychologists

77. Cultural Influences

78. Twins' Answers on Personality Test Questions

79. Do MZA Pairs Grow Up in Different (Uncorrelated) Environments?

80. Similar Appearance

81. Other Cohort Effects

82. Range Restriction

83. Epigenetics

84. Conclusions

85. Notes

5 The Minnesota Study of Twins Reared Apart I Biases, Assumptions, and Other Problem Areas

87. The MISTRA Twin Sample

88. DZA Pairs: The MISTRA Designated Control Group

89. MZA versus DZA Correlations

90. How the Researchers Arrived at Conclusions in Favor of Genetics

91. Finding # 1: The MZA Correlation is Significantly Higher than the DZA Correlation

92. Finding # 2: The MZA correlation is Assumed to Directly Estimate Heritability

93. Finding # 3: Model-Fitting Procedures Produce Substantial Heritability Estimates

94. Assumptions That Are “Likely Not to Hold”

95. Did the MISTRA MZA Pairs Experience Less Similar Environments than Pairs in the Previous Studies?

96. Recruitment Bias

97. Age and Sex Confounds

98. Reliance on Twins' Accounts of Separation and Behavioral Similarity

99. Sample Size

100. Confirmation Bias

101. A Gene for Pinkie Finger Curling?

102. Failure to Make the Data Available for Inspection and Analysis

103. A 1991 Exchange in Science

104. The MISTRA Researchers and Leon Kamin

105. Use of the MISTRA Findings by Disreputable Groups

106. Access to the Data Must Become a Requirement

107. Conclusion: The MISTRA was Based on a Large Number of Questionable Assumptions and Concepts

108. Notes

6 The Minnesota Study of Twins Reared Apart II IQ and Personality Studies

110. MISTRA IQ Studies

111. Early Reports

112. Two 1990 Publications

113. The 1990 Science article

114. The 1990 Acta Geneticae Medicae et Gemellologiae article

115. Subsequent Reporting (and Non-Reporting) of the MISTRA DZA IQ correlations

116. Bouchard, 1991

117. Bouchard, 1993

118. McGue, Bouchard, Iacono, and Lykken, 1993

119. Bouchard, 1994

120. Bouchard, Lykken, Tellegen, and McGue, 1996

121. Bouchard, 1996

122. Bouchard, 1997

123. Bouchard, 1997

124. McGue and Bouchard, 1998

125. Newman, Tellegen, and Bouchard, 1998

126. Bouchard, 1998

127. Segal, 1999

128. Bouchard and Pedersen, 1999

129. McCourt, Bouchard, Lykken, Tellegen, and Keyes, 1999

130. Bouchard and McGue, 2003

131. Segal, 2003

132. Johnson, Bouchard, McGue, Segal, Tellegen, Keyes, and Gottesman, 2007

133. Segal and Johnson, 2009

134. Segal, 2012

135. Bouchard, 2013

136. Bouchard, 2014

137. Evaluation of the MISTRA Cognitive Ability Studies

138. MISTRA Personality Studies

139. Tellegen and Colleagues, 1988

140. Two 1990 Publications

141. Subsequent MISTRA Personality Studies

142. Evaluation of the MISTRA Personality Studies

143. Conclusions

144. Notes

145. II Studies of Reared-Together Twins

7 The Mzt–Dzt Equal Environment Assumption The Achilles Heel of the Classical Twin Method

147. The Traditional Definition of the EEA

148. The “Fallacy” of the Twin Method

149. The Two Main Arguments Put Forward in Defense of the Equal Environment Assumption

150. Argument A

151. Argument B

152. Argument A Potentially Renders Argument B Irrelevant

153. Identity Confusion and Attachment

154. Family Studies and the Twin Method

155. A 2012 Defense of the Equal Environment Assumption

156. Points # 1 and # 2: MZT Pairs Have More Similar Experiences, and Influence Each Other More, Than DZT pairs

157. From Argument B . . . to Argument A

158. Point # 3: Is More Similar Treatment (Based on Similar Appearance) a Genetic Effect?

159. Point # 4: Do Prenatal (Intrauterine) Environmental Differences Support Genetic Interpretations?

160. “An Obviously Confounded, Unreliable Methodology”

161. Conclusions

162. Notes

8 Twin Research in Psychiatry

164. The Equal Environment Assumption in Psychiatric Twin Research

165. Psychiatric Genetic Defenses of the EEA

166. Kendler

167. Flint, Greenspan, and Kendler

168. Problems with Psychiatric Diagnoses

169. Reliability and Validity

170. The DSM-5 and Genetics

171. Schizophrenia: The Classic Psychiatric Diagnosis

172. Environmental Factors that Contribute to Schizophrenia and Psychosis

173. An Implicit Assumption of Genetic Theories in Psychiatry

174. An Article Emblematic of the Failures of Psychiatric Genetics

175. Is Psychiatric Genetics Moving Toward the Status of a “Null Field”?

176. Conclusions

177. Notes

178. III Approaching a Post-Behavioral- Genetics Era?

9 Molecular Genetic Research The Ultimate Test of Genetic Interpretations of Twin Studies

180. Current Status

181. Cognitive Ability (IQ)

182. Personality and Behavior

183. Psychiatric Disorders

184. The “Missing Heritability” Explanation

185. Challenging the Missing Heritability Position

186. Missing Heritability and the Human Genome Project

187. Four Key Problems with the Missing Heritability Argument

188. Missing Heritability and the MISTRA

189. A New Approach

190. Negative Results, Once Again

191. A Faltering Paradigm?

192. Conclusions

193. Notes

10 The Crumbling Pillars of Behavioral Genetics

195. Three and a Half Decades of Claims and Predictions

196. 1978–1990

197. 1991–1995

198. 1996–1999

199. 2000–2002

200. 2003–2004

201. 2005–2011

202. 2012–2014

203. Conclusions

204. Notes

11 A Human Genetics Parable

206. Introduction

207. A Human Genetics Parable

208. Notes

12 Summary and Conclusions

210. A Final Evaluation of Twin Research

211. Appendix A: The Funding of MISTRA

212. The Pioneer Fund

213. Segal on the Pioneer Fund

214. Rushton and Lynn

215. Notes

216. Appendix B: A Little-Known Behavioral Genetic Adoption Study Whose Results Contrast with the MISTRA Personality Findings

217. Overview of the Study

218. Alternative Explanations of the Results

219. The Converging Evidence Argument

220. Heritability and Model Fitting

221. The 1998 CAP Study and the Twin Method

222. The 1998 CAP Study and the MISTRA

223. The 1998 CAP Study's Lack of Impact

224. Conclusions

225. Notes

226. 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

227. (All quotations refer to twins reared together: MZTs and DZTs)

228. Glossary

229. References

230. Index