Scientific myths persist despite evidence

Published on Tuesday 7 April 2009 22:22

THE "criminal chromosome" and a gene for intelligence are scientific ideas that people continue to believe despite evidence disproving them, a leading scientist said yesterday.

Professor Jon Beckwith, professor of molecular genetics at Harvard Medical School, said even when these theories were proved wrong, they continued to affect social policy and people's lives.

He told an Edinburgh Science Festival event that scientists and scientific journals needed to think more carefully when presenting their research, rather than pushing ideas with scant evidence to back them up.

Prof Beckwith highlighted a number of examples where research appeared to make dramatic claims that were later disproved.

One such study was conducted at Carstairs state hospital in 1965. Prof Beckwith said it found that about 3 per cent of inmates had an extra Y chromosome – the structures in cells that carry genetic information.

This extra chromosome came to be known as the "criminal chromosome" which some said was linked to a tendency for criminal behaviour.

Prof Beckwith said: "It was picked up quite strongly. In fact the next year, people charged with murder or convicted of murder claimed they were XYY males and it wasn't their fault."

Prof Beckwith said that subsequent studies showed that the evidence did not stack up, yet the idea of the criminal chromosome persisted, even appearing in films and television shows.

A spokeswoman for charity Sense About Science said: "We regularly see dubious ideas that are delivered with a front-page fanfare, but the later refutation fizzles out as an overlooked footnote.

"When we succeed at making the underlying science clearer, the public debate catches on more quickly. This is a tough challenge for science."