Scientific heresy

Like antisepsis, many scientific truths began as heresies and fought long battles for acceptance against entrenched establishment wisdom that now appears irrational: continental drift, for example. Barry Marshall was not just ignored but vilified when he first argued that stomach ulcers are caused by a particular bacterium. Antacid drugs were very profitable for the drug industry. Eventually he won the Nobel prize.

Just this month Daniel Shechtman won the Nobel prize for quasi crystals, having spent much of his career being vilified and exiled as a crank. “I was thrown out of my research group. They said I brought shame on them with what I was saying.”

That’s lesson number 4: the heretic is sometimes right.

What sustains pseudoscience is confirmation bias. We look for and welcome the evidence that fits our pet theory; we ignore or question the evidence that contradicts it. We all do this all the time. It’s not, as we often assume, something that only our opponents indulge in. I do it, you do it, it takes a superhuman effort not to do it. That is what keeps myths alive, sustains conspiracy theories and keeps whole populations in thrall to strange superstitions.

Bertrand Russell pointed this out many years ago: “If a man is offered a fact which goes against his instincts, he will scrutinize it closely, and unless the evidence is overwhelming, he will refuse to believe it. If, on the other hand, he is offered something which affords a reason for acting in accordance to his instincts, he will accept it even on the slightest evidence.”

Lesson no 5: keep a sharp eye out for confirmation bias in yourself and others.

There have been some very good books on this recently. Michael Shermer’s “The Believing Brain”, Dan Gardner’s “Future Babble” and Tim Harford’s “Adapt” are explorations of the power of confirmation bias. And what I find most unsettling of all is Gardner’s conclusion that knowledge is no defence against it; indeed, the more you know, the more you fall for confirmation bias. Expertise gives you the tools to seek out the confirmations you need to buttress your beliefs.

Experts are worse at forecasting the future than non-experts.

Philip Tetlock did the definitive experiment. He gathered a sample of 284 experts – political scientists, economists and journalists – and harvested 27,450 different specific judgments from them about the future then waited to see if they came true. The results were terrible. The experts were no better than “a dart-throwing chimpanzee”.

Here’s what the Club of Rome said on the rear cover of the massive best-seller Limits to Growth in 1972:

“Will this be the world that your grandchildren will thank you for? A world where industrial production has sunk to zero. Where population has suffered a catastrophic decline. Where the air, sea and land are polluted beyond redemption. Where civilization is a distant memory. This is the world that the computer forecasts.”

"Science is the belief in the ignorance of the experts", said Richard Feynman.