The US president-elect Barack Obama was in unusual company last week, appearing alongside showbiz celebrities such as the actress Demi Moore and the singer Mariah Carey. There was little glitz on show, however, as this public outing took the form of a report in which he and many other public figures were upbraided for talking scientific tosh. Published late last month by the UK-based campaigning organisation Sense About Science, the report took the three to task for various crimes against science committed over the last 12 months, and asked that they try harder in future - by asking experts before giving the world the benefit of their views.
To be frank, Ms Carey's crime was hardly eye-rollingly egregious. Asked to explain why the title of her most recent album takes the form of Einstein's famous equation relating mass and energy, E = mc2, she told a magazine that "It's sort of like emancipation equals Mariah Carey times two". Okay, so she mixed up doubling with taking squares; all that tells us is that her grasp of algebra is on a par with Einstein's ability to sing across five octaves.
Rather more worrying was Demi Moore's public assertion last year that she's a committed user of leeches which she claims are a wonderful way of "detoxifying" the blood. "They have a little enzyme that when they're biting down on you, gets released into your blood", she told chat show host David Letterman. "And your health is optimised". Really ? It's a view unlikely to be shared by any doctor who qualified in the last century or so.
It's unlikely that anyone looking for an understanding of the mass-energy relation in relativity or the role of the anticoagulant peptide secreted by Hirudo medicinalis would turn to a pop singer or actress. But the views of the president-elect of the US on the link between childhood vaccinations and autism certainly do merit attention. "Some people are suspicious that it's connected to the vaccines," he said last year, adding: "The science right now is inconclusive, but we have to research it."
As the Sense About Science report pointed out, Mr Obama could do worse than to listen to the Hollywood actress Amanda Peet, who won plaudits for knowing that the evidence is now anything but inconclusive: "Fourteen studies have been conducted," she said recently. "And these tests are reproducible; no matter where they are administered, or who is funding them, the conclusion is the same: there is no association between autism and vaccines".
The campaigners at Sense About Science are right to worry about celebrities spreading scientific mis-information, given the influence such people can have on the public. But their recommendation that celebrities talk to a scientist before wading into a controversy is based on a big assumption - namely, that scientists are always right. The fact is that it's surprisingly easy to find scientists willing to lend their support to a host of crackpot ideas, from the causes of disease to the creation of the world in six days flat. Just ask Thabo Mbeki, the former president of South Africa, who was able to enlist the services of the renegade biologist Professor Peter Duesberg of Berkeley University, California, to back his claim that the HIV virus is not responsible for Aids - a lethally invalid argument recently blamed for costing the lives of hundreds of thousands of South Africans.
Mr Mbeki is just one of the more recent examples of leaders who have inflicted untold misery on their population through the dodgy advice of "experts". During the 1920s, Josef Stalin helped contribute to mass-starvation in the Soviet Union by adopting the crackpot theories of Trofim Lysenko, an agronomist who rejected the "bourgeois" science of genetics. Lysenko had developed a new system of agriculture based partly on the discredited notion that traits acquired during the lifetime of organisms could be passed on to later generations. With Stalin's support, Lysenko came to dominate Soviet biology until the 1960s - with catastrophic consequences for Soviet crop yields.
Some of Mr Obama's predecessors as occupants of the White House believed there were scientific reasons for not letting mixed-race people anywhere near the place. President Calvin Coolidge, a convinced eugenicist, declared that "Biological laws show that Nordics deteriorate when mixed with other races" - a view shared by many scientists at the time. During the 1920s many US states enacted eugenic policies which by the late 1970s had led to more than 60,000 sterilisations of "defectives". As recently as the 1980s, the Nobel-Prizewinning American scientist William Shockley was cheerfully espousing the cause of eugenics, and suggesting that individuals with below-average IQs be paid to undergo voluntary sterilisation.
During the 1950s, celebrities fretting about their endorsement of cigarettes could have the mounting statistical evidence for a link with cancer denounced by the world's leading statistician, Professor Sir Ronald Fisher of Cambridge University. Evidence that cigarettes cause lung cancer first emerged in the 1920s and became all but undeniable by the 1950s, but Sir Ronald would have none of it. He argued that it was possible that there was a gene which both caused cravings for cigarettes and increased the chances of developing lung cancer, thus creating the illusion of a link. He even suggested that lung cancer was a disease whose symptoms led people to take up smoking in search of relief.
Studies of identical twins - who share the same genes - and a mass of further statistical evidence eventually proved Fisher wrong. Those who knew him insisted that the fact he was a paid consultant of the tobacco industry had no bearing on his views. Instead, they pointed to his life-long loathing of finger-wagging puritans - and his smoking habit. So we have been warned: the views of even a world-renowned scientist may be no more rational than those of a celeb with a 60-a-day habit and a problem with authority.
Robert Matthews is Visiting Reader in Science at Aston University, Birmingham, England
