Embryos should not be selected for behavioural traits such as intelligence on the basis of genetic information, according to a Report published today (2 October) by the Nuffield Council on Bioethics. The report, Genetics and human behaviour: the ethical context, looks at ethical, legal and social issues that are raised by research into behavioural genetics.

Research to find out how our genes influence our behaviour is complex and controversial. “This is a potentially explosive area,” says Professor Bob Hepple, QC, Chairman of the Working Party and Master of Clare College, Cambridge, “and the first question we asked was whether such research should be carried out at all. We concluded that it can be justified because it has the potential to advance our understanding of human behaviour. However, it is important to create safeguards to protect against its misuse.”

The Working Party assessed the evidence to date of associations between genetic variants and behaviour, considering traits such as intelligence, antisocial behaviour, personality traits and sexual orientation. The focus was on behaviours within the normal range of variation, rather than those thought of as diseases or disorders, such as depression. So far, despite a number of highly publicised claims, no genetic variant has been shown conclusively to influence antisocial behaviour, intelligence in the normal range, or sexual orientation.

“The term a ‘gene for X’ is misleading,” comments Professor Hepple. It is unlikely that variation in just one gene contributes to a trait. Many genes, each having a very small effect, are likely to be involved and the environment also plays an important role. “We should not overestimate the predictive power of genes,” continues Professor Hepple. “It is important to point out that the effects of genes are not inevitable.”

Selection of embryos

There are currently no practical applications of research in the genetics of behaviour within the normal range. But it is not too soon to examine ethical and social issues raised by potential developments. For example, it may become possible to select embryos which are more likely to have a particular behavioural trait, such as above average intelligence.

One way of doing this would be by preimplantation genetic diagnosis. Currently, the selection of embryos using this method is restricted to serious diseases. “We recommend that preimplantation genetic diagnosis should not be extended to allow selection of embryos for behavioural traits within the normal range,” says Professor Tom Baldwin, a member of the Working Party and Head of the Department of Philosophy at the University of York.

Impact on the criminal justice system

Information about genetic influences on behaviour also has implications for the criminal justice system. Could a genetic explanation for antisocial behaviour be used to excuse an offender? The Report concludes that genetic information about behaviours within the normal range does not absolve an individual from responsibility for an offence. However, the information could be taken into account by judges when sentencing, in the same way that environmental factors, such as poverty or an abusive childhood, may be considered. If the information is to be used in this way, it is vital that the genetic link is convincing, and that the tests are accurate and reliable.

It is unlikely that genetic information will be accurate enough to justify using it on its own to predict antisocial behaviour. “Where a person has not yet committed a crime, we do not feel that it is justifiable to try to predict behaviour with a view to detaining that individual. This applies equally whether the information is based on genetic or non-genetic influences,” says Professor Hepple.


The Working Party was concerned that research in behavioural genetics might exacerbate the trend towards medicalisation, with people increasingly encouraged to take medication to alter behaviours previously considered ‘normal’. “This could lead to unnecessary increased expenditure by the Health Service. We recommend that the Department of Health should ensure that the deliberate prescribing of medicines for behavioural traits within the normal range be monitored and, if necessary, controlled,” says Professor Baldwin. “We must also be careful that genetic or medical interventions are not routinely adopted without adequate consideration being given to environmental approaches.”

The Report also addresses issues raised by the use of genetic information about behaviour in the contexts of employment, education and insurance, and considers the question of regulating the provision of genetic tests or interventions aimed at altering behaviour. “We hope that this Report – the first in the area – will stimulate debate and discussion between scientists, policy makers, and the public about the ethical and legal implications of behavioural genetics. We call on policy-makers to begin to consider how to monitor and regulate the applications of this research. If we put safeguards in place now we should be able to prevent potential abuses in the future,” concludes Professor Hepple.

Notes for editors:

1. Copies of the Report can be downloaded from the Council’s website.

2. The Nuffield Council on Bioethics is an independent body which examines the ethical issues raised by developments in medicine and biology. Established in 1991, it is funded by The Nuffield Foundation, the Medical Research Council and The Wellcome Trust.

3. Members of the Working Party

Professor Bob Hepple QC (Chairman)
Master, Clare College, Cambridge

Professor Martin Bobrow CBE
Head of Department of Medical Genetics, University of Cambridge, Deputy Chairman of the Nuffield Council on Bioethics

Professor Tom Baldwin
Head of Department of Philosophy, University of York, Member of the Nuffield Council on Bioethics

Professor Annette Karmiloff-Smith
Head of Neurocognitive Development Unit, Institute of Child Health, University College London

Professor Sandy McCall-Smith
Professor of Medical Law, University of Edinburgh

Professor Terrie Moffitt
Social, Genetic and Developmental Psychiatry Research Centre, Institute of Psychiatry, King’s College London

Dr Paul Pharoah
CRC Senior Clinical Research Fellow, Strangeways Research Laboratories, Cambridge

Professor Nicholas Rawlins
Professor of Behavioural Neuroscience, University of Oxford

Professor Martin Richards
Centre for Family Research, University of Cambridge

Mr Pushpinder Saini
Blackstone Chambers, Temple

Dr Tom Shakespeare
Policy, Ethics and Life Sciences Research Institute, International Centre for Life, Newcastle

Professor Anita Thapar
Professor of Child and Adolescent Psychiatry, University of Wales College of Medicine

Professor Andrew Wilkie
Wellcome Senior Clinical Fellow, Honorary Consultant in Medical Genetics, Institute of Molecular Medicine, University of Oxford

4. Seminar: Wednesday 2 October, 2.00 - 5.00 pm
An in-depth seminar providing an opportunity for professionals, researchers and interested members of the public to discuss the Report’s recommendations with members of the Working Party. Admission is free, but places must be reserved in advance.