Fifty years to the day from the discovery of the structure of DNA, one of its co-discoverers has caused a storm by suggesting that stupidity is a genetic disease that should be cured.

On 28 February 1953 biologists James Watson and Francis Crick discovered the structure of DNA - the chemical code for all life. The breakthrough revealed how genetic information is passed from one generation to the next and revolutionised biology and medicine.

But in a documentary series to be screened in the UK on Channel 4, Watson says that low intelligence is an inherited disorder and that molecular biologists have a duty to devise gene therapies or screening tests to tackle stupidity.

"If you are really stupid, I would call that a disease," says Watson, now president of the Cold Spring Harbour Laboratory, New York. "The lower 10 per cent who really have difficulty, even in elementary school, what's the cause of it? A lot of people would like to say, 'Well, poverty, things like that.' It probably isn't. So I'd like to get rid of that, to help the lower 10 per cent."

Watson, no stranger to controversy, also suggests that genes influencing beauty could also be engineered. "People say it would be terrible if we made all girls pretty. I think it would be great." [...]