Journal of Applied Philosophy Vol 23 No 2 2006 Behavioural Genetics 157 Behavioural Genetics Why Eugenic Selection is Preferable to Enhancement JULIAN SAVULESCU MELANIE HEMSLEY AINSLEY NEWSON AND BENNETT FODDY Criminal behaviour is but one behavioural tendency for which a genetic influence has been suggested Whilst this research certainly raises difficult ethical questions and is subject to scientific criticism one recent research project suggests that for some families criminal tendency might be predicted by genetics In this paper supposing this research is valid we consider whether intervening in the criminal tendency of future children is ethically justifiable We argue that if avoidance of harm is a paramount consideration such an intervention is acceptable when genetic selection is employed instead of genetic enhancement Moreover other moral problems in avoiding having children with a tendency to criminal behaviour such as the prospect of social discrimination can also be overcome I Introduction Recent discoveries in human behavioural genetics indicate putative associations between specific genetic markers and a range of complex traits including criminal tendency 1 Unlike many such projects dogged by retractions one subset of criminal tendency research has produced compelling results the correlation of mutations in the monoamine oxidase A gene and criminal behaviour within a Dutch criminal kindred If this research proves valid questions will inevitably arise about the moral acceptability of couples using reproductive technology to avoid having a child with criminal tendency In this paper we employ this Dutch criminal kindred research to discuss the morality of selecting against criminality in future children After briefly tracing the history and controversy of eugenics and behavioural genetics research we summarise the theory that biochemical pathways involving monoamine oxidase can influence a person s chances of engaging in criminal behaviour at some point in their lives We then utilise this example to argue drawing on Parfit s non identity problem that choosing children without mutations in their monoamine oxidase A genes is acceptable particularly if genetic selection technology is employed over genetic enhancement This is because genetic selection is more immune than genetic enhancement to arguments depending on concepts of harm to the child However genetic selection remains subject to other objections not met by the use of this technique which could affect its immunity to arguments based on harm to the child Therefore we consider potential problems such as the child s right to an open future privacy and parental expectations We also consider arguments derived from social harms such as diversity and discrimination Society for for Applied Applied Philosophy Philosophy 2006 2006 Blackwell Publishing 9600 Garsington Road Oxford OX4 2DQ UK and 350 Main Street Malden MA 02148 USA 158 J Savulescu M Hemsley A Newson and B Foddy We conclude that if used in a controlled and appropriate way with due concern for possible outcomes genetic selection to avoid criminal tendency is morally justifiable II Behavioural Genetics and Eugenics Research into genetics and criminality is of course haunted by the spectre of eugenics From the late 19th century until after the Second World War this movement in Europe and North America aimed to enhance the genetic pool Proponents of eugenics desired to eradicate genes for those complex behaviours deemed undesirable such as criminality psychiatric disease and mental retardation They sought to encourage those judged to have a superior genetic constitution to reproduce whilst discouraged the genetically unfit from so doing sometimes involving involuntary sterilisation 2 In the United States the first sterilisation law was passed in Indiana in 1907 Over the next ten years fifteen more states passed legislation which empowered them to sterilise habitual or confirmed criminals or persons guilty of some particular offence like rape 3 A statute in Iowa went so far as to require the sterilisation of twiceconvicted sexual offenders of thrice convicted other felons and of anyone convicted just once of involvement in white slavery 4 Following the human rights abuses of the Second World War and eugenic practices of this nature rapidly and justifiably fell from favour Not only was this movement based on questionable normative assumptions it was bad science and exemplified crude genetic determinism 5 Heredity is clearly not the sole causal determinant for human behavioural and mental traits and state fair charts declaring that unfit human traits such as feeblemindedness epilepsy criminality insanity alcoholism pauperism and many others run in families and are inherited in exactly the same way as colour in guinea pigs 6 were rightly abandoned Following the discrediting of determinism statutes sanctioning sterilisation of various groups including criminals were gradually repealed However attempts to establish a link between biology and criminal tendency continued during the 1960s and 1970s For example researchers aimed to establish a link between criminal tendency and the XYY karyotype and criminal tendency and testicular size These studies again were liable to criticism from an epistemological perspective providing more shady milestones in the history of behavioural genetic research 7 Given the bleak history of behavioural genetics public concern with research into criminal tendency is certainly understandable It is likely that genetic influences on behaviour if they exist at all are so complex that any research undertaken will always be prone to a low level of accuracy 8 This tendency to low accuracy may even lead to results derived from researcher bias such as racism rather than scientific rigour 9 Yet despite public concern research into genetic influences on criminal tendencies has failed to decline In fact recent research suggests that a link between genetics and criminality is not only possible but likely And with the recent completion of the Human Genome Project it is possible that more genes will be discovered to significantly influence our behaviour In one family at least this already appears to be the case Society for Applied Philosophy 2006 Behavioural Genetics 159 III The Dutch Family Criminal Kindred III 1 Disproportionate Displays of Criminal Behaviour The most compelling evidence of a genetic link to a form of criminal behaviour derives from the