Controversial research into the genetics of mental ability has been delayed for at least nine months after the Medical Research Council declined to award it a grant in its latest round.
The research has been delayed for several reasons, including refinement of its design and the arrival of a top statistical geneticist. But it has also been delayed so that ethical issues can be addressed.
The researchers plan to gather the DNA of all twins born between 1994 and 1996 and relate genetic and environmental differences to any mild mental impairment.
It has been planned by the Social, Genetic and Developmental Psychiatry Research Centre, set up by the Institute of Psychiatry in south London with a Pounds 6 million grant from the MRC. The centre has also attracted some top US scientists, also funded by the MRC. These include Robert Plomin, who is heading the twin study, and the more recently acquired David Fulker, billed by the centre as the world's foremost statistical geneticist.
Professor Plomin, who would not comment on the decision, had asked the MRC for Pounds 1.8 million. Instead, the MRC has set up a working group, led by George Radda, the next head of the MRC. It will run a workshop in the autumn to devise a framework from which it can assess the ethics of studies in behavioural genetics. An MRC spokesperson said: "Here is almost a new area for ethical consideration."
The research involves quantitative trait loci analysis, a risk analysis that enables scientists to assess traits that may involve many genes as well as environmental factors.
Sir Michael Rutter, who directs the centre, said that the workshop would "look at the broader issues of QTL research".
"When moving into a new research field questions are naturally raised as to what are the risks, benefits, ethical issues and hazards to be avoided," he said. "Everyone is in favour of an open and transparent approach. The answer will be that if it is properly done this is perfectly ethical and highly desirable."
Professor Plomin's plans have been criticised as a search for the genetics of IQ, and thus socially dangerous. Professor Rutter said: "It would be naive to suppose that that hasn't been a factor."