Genetics and - Nuffield Bioethics

1 Published by Nuffield Council on Bioethics28 Bedford SquareLondon WC1B 3 JSTelephone: 020 7681 9619 Fax: 020 7637 1712 Internet: screening: ethical issuesPublished December 1993 human tissue: ethical and legal issuesPublished April 1995 Animal-to- human transplants: the ethics of xenotransplantationPublished March 1996 Mental disorders and Genetics : the ethical contextPublished September 1998 Genetically modified crops: the ethical and social issuesPublished May 1999 The ethics of clinical research in developing countries: a discussion paperPublished October 1999 Stem cell therapy: the ethical issues a discussion paperPublished April 2000 The ethics of research related to healthcare in developing countriesPublished April 2002 The ethics of patenting DNA: a discussion paperPublished July 2002 Genetics and human behaviour : the ethical context Nuffield Council on BioethicsGenetics andhuman behaviourthe ethical contextCover final A/W13657 19/9/02 11:52 am Page 1 Published byNuffield Council on Bioethics28 Bedford SquareLondon WC1B 3 JSTelephone: 020 7681 9619 Fax:020 7637 1 904384 03 XOctober 2002 Price inc p + p (both national and international)Please send cheque in sterling with order payable to NuffieldFoundation Nuffield Council on Bioethics 2002 All rights reserved.

2 Apart from fair dealing for the purpose ofprivate study, research, criticism or review, no part of thepublication may be produced, stored in a retrieval system ortransmitted in any form, or by any means, without prior permissionof the copyright by dsprint/redesign7 Jute LaneBrimsdownEnfield EN3 7JL Printed byLatimer Trend & Company Ltd Estover Road Plymouth PL6 7 PLCover final A/W13657 19/9/02 11:52 am Page 2 Genetics andhumanbehaviour: theethical contextPRELIMS 13657 17/9/02 9:20 am Page iiiPRELIMS 13657 17/9/02 9:20 am Page iiiiiNuffield Council on BioethicsProfessor Sir Ian Kennedy(Chairman)Professor Martin Bobrow CBE (Deputy Chairman)Professor Tom BaldwinMs Rebecca Burke CBEP rofessor Sir Kenneth Calman KCB FRSEThe Rt Rev Richard Harries DD FKC FRSLP rofessor Bob Hepple QCProfessor John LedinghamProfessor Catherine Peckham CBEP rofessor Martin RaffMr Nick RossProfessor Herbert SewellProfessor Dame Marilyn Strathern FBAP rofessor Albert Weale FBADr Alan Williamson FRSES ecretariatDr Sandy Thomas (Director)Ms Tor LezemoreMs Susan Bull (until April 2002)Mr Harald Schmidt (from May 2002)Mrs Julia FoxMs Yvonne Melia (until April 2002)Ms Natalie Bartle (from June 2002)Ms Nicola PerrinMs Elaine Talaat-AbdallaMs Maria Gonzalez-NogalThe terms of reference are as follows:1to identify and define ethical questions raised by recent advances in biological and medicalresearch in order to respond to, and to anticipate, public concern.

3 2to make arrangements for examining and reporting on such questions with a view topromoting public understanding and discussion; this may lead, where needed, to theformulation of new guidelines by the appropriate regulatory or other body;3in the light of the outcome of its work, to publish reports; and to make representations, as theCouncil may judge Nuffield Council on Bioethics is funded jointly by the Medical Research Council, the Nuffield Foundation and the Wellcome TrustPRELIMS 13657 17/9/02 9:20 am Page iiiivPRELIMS 13657 17/9/02 9:20 am Page ivvPrefaceI was apprehensive when asked by the Nuffield Council on Bioethics to chair the WorkingParty which has produced this Report. First, because the subject has an ugly history: withinliving memory perverted science was put at the service of ideologies that led to thesubjugation and even extermination of people judged to be genetically inferior .Secondly, because modern behavioural Genetics is rich in promise but, as yet, poor in hardverifiable evidence.

4 Thirdly, because it seemed unlikely that one would be able to reachany agreed recommendations in this highly complex and controversial these fears have been dispelled over the past two years in which the Working Partyhas met eleven times, held six fact-finding sessions with more than twenty experts,commissioned reviews of the scientific evidence, and undertaken a public became clear that this investigation, believed to be the first of its kind, is necessary ifwe want to avoid the mistakes of the past, make an impartial assessment of theemerging scientific evidence, and reach valid moral and legal conclusions about thepotential applications of the research. The agreed recommendations are important, butperhaps even more significant are the careful explanation that we have attempted togive of the methods of research in this area, the assessment of the current evidence forgenetic influences on behaviour, and the balanced discussion of the ethical and legalchoices that lie ahead.

5 Our expectation is that this Report will help non-specialists tounderstand what behavioural Genetics aspires to achieve, what has thus far beenachieved and equally importantly, how much has not yet been achieved. We hope thatit will promote an informed debate between scientists, policy makers, and the lay publicabout the ethical and legal should like to thank the members of the Working Party for their hard work anddedication; working with them was an enjoyable and stimulating experience. We are allgrateful to Dr Sandy Thomas, Director of the Nuffield Council on Bioethics , for herguidance and sound judgment. Tor Lezemore made a truly outstanding contribution as ourinventive scribe, editor and secretary; her sparkling humour and enthusiasm kept us are also due to Julia Fox, Yvonne Melia, Susan Bull, Natalie Bartle and Nicola Perrinfor their support. Finally, since this is the last Report which will be published under Sir IanKennedy s chairmanship of the Nuffield Council on Bioethics , I should like to pay tribute tohis enormous contribution to Bioethics in general, and to his role as mentor of thisWorking Party in Hepple QCPRELIMS 13657 17/9/02 9:20 am Page vviAcknowledgementsThe Working Party wishes to thank the many organisations and individuals who haveassisted its work, particularly those who attended fact-finding meetings or submittedresponses to the public consultation.

6 The Working Party is very grateful to Professor SirRobert Hinde, Professor Erik Parens, Professor Nikolas Rose, Tim Radford and ProfessorSir Michael Rutter, who all reviewed an earlier draft of the Report. Their commentscontained constructive criticisms and suggestions for further discussion, which wereextremely helpful. The Working Party would like to thank the following individualsfrom whom it commissioned papers reviewing the scientific evidence in research inbehavioural Genetics : Professor John Crabbe, Professor Jeffery Gray, Professor NicholasMackintosh and Professor Terrie Moffitt. The Working Party is also grateful to individualswho responded to requests for advice on specific parts of the Report, including DrJonathan Flint, Mrs Nicola Padfield and Professor Mark 13657 17/9/02 9:20 am Page viviiTable of ContentsCouncil membership and terms of viWorking Party xiiiWorking Party terms of xvSummary and xixSection I: Introduction and contextChapter 1: 3 Why this Working Party is 5 Defining the normal range of behavioural 7 The scope of research in behavioural Genetics .

7 8 The structure of the Report .. 8 Chapter 2: The historical 11 The impact of eugenic thought on research into human behaviour .. 18 Psychology in the first half of the twentieth century .. 18 Psychology from the 1960s 20 Individual differences .. 20 Evolutionary psychology .. 21 Processes of development .. 21 Conclusion .. 22 Section II: Scientific backgroundChapter 3: Research in behavioural 25 Introduction .. 27 What is genetic variation? .. 29 What is meant by normal variation in human behaviour? .. 31 A gene for X ? .. 32 Describing human behaviour .. 35 Predicting human behaviour from genetic information .. 36 Chapter 4: Quantitative Genetics : measuring 37 Introduction .. 39 How is population variation examined using genetic studies?.. 39 Genetic influences on 39 Genetics and human behaviour:the ethical contextPRELIMS 13657 17/9/02 9:20 am Page viiviiiEnvironmental influences on variation .. 41 Gene-environment correlation and interaction .. 41 Family, twin and adoption 42 Family studies.

8 42 Studies of 42 Methods .. 42 Interpretation of twin study findings .. 43 Adoption studies .. 44 Current uses of quantitative genetic studies .. 45 Conclusion .. 46 Chapter 5: Identifying genetic factors contributing to individual differences in behaviour. 47 Introduction .. 49 Approaches to identifying susceptibility alleles .. 49 Linkage studies .. 50 Association studies .. 51 Identification of alleles that influence behaviour .. 52 Scaling up the analysis: new methods in Genetics .. 52 Conclusion .. 53 Chapter 6: Research in behaviour Genetics involving animals .. 55 Introduction .. 57 How are animal models created?.. 58 What are the benefits of using animals to study the Genetics of human behaviour?.. 60 What are the problems with using animals to study the Genetics of human behaviour? .. 63 Part III: Reviews of the evidenceChapter 7: 67 Background .. 69 Trait definition and measurement .. 69 Current findings: quantitative Genetics .. 71 Current findings: molecular Genetics .

9 73 Directions for future research .. 76 Chapter 8: 81 Trait definition and measurement .. 81 Current findings: quantitative Genetics .. 83 Current findings: molecular Genetics .. 84 Quantitative trait loci 85 Current findings: research involving animals .. 85 Future directions for research .. 86 PRELIMS 13657 17/9/02 9:20 am Page viiiixChapter 9: Antisocial 87 Background .. 89 Trait definition and measurement .. 89 Current findings: quantitative Genetics .. 91 Antisocial 93 Sex differences .. 94 Current findings: molecular Genetics .. 95 Current findings: research involving animals .. 95 Future directions from research .. 96 Chapter 10: Sexual 97 Background .. 99 Trait measurement and definition .. 99 Current findings: quantitative Genetics .. 100 Twins and adopted siblings .. 101 Male homosexuality .. 101 Female homosexuality .. 102 Current findings: molecular Genetics .. 102 Current findings: research involving animals .. 103 Current findings: other biological 104 Critical assessment of the validity of this arguments against genetic influences on homosexuality.

10 106 Future directions for research .. 107 Chapter 11: Themes from the reviews of the 109 Introduction .. 111 The difficulty of defining and measuring traits .. 111 Estimates of heritability .. 111 The lack of replicated findings in molecular Genetics .. 112 Applications of current research 112 Reporting research in behavioural Genetics .. 113 Funding research in behavioural Genetics .. 114 Conclusion .. 115 Part IV: ethical , legal, social and policy issuesChapter 12: Genetics , freedom and human 119 The material self .. 122 Determinism and 123 Freedom, possibility and 124 Eliminating rationality .. 125 Accommodating 126 PRELIMS 13657 17/9/02 9:20 am Page ixxThe implications of behavioural Genetics .. 128 Conclusion .. 130 Chapter 13: Selecting and changing behavioural 131 Introduction .. 133 Will there be any practical applications of research in behavioural Genetics .. 133 Genetic interventions .. 134 Medical 135 Environmental interventions .. 135 Medicalising human behaviour.