Maybe we're all conspiracy theorists - Matt Ridley

My latest Wall Street Journal Mind and Matter column discusses conspiracy theories.

Michael Shermer, the founder and editor of Skeptic magazine, has never received so many angry letters as when he wrote a column for Scientific American debunking 9/11 conspiracy theories. Mr. Shermer found himself vilified, often in CAPITAL LETTERS, as a patsy of the sinister Zionist cabal that deliberately destroyed the twin towers and blew a hole in the Pentagon while secretly killing off the passengers of the flights that disappeared, just to make the thing look more plausible.

He tells this story in his fascinating new book, “The Believing Brain.” In Mr. Shermer’s view, the brain is a belief engine, predisposed to see patterns where none exist and to attribute them to knowing agents rather than to chance-the better to make sense of the world. Then, having formed a belief, each of us tends to seek out evidence that confirms it, thus reinforcing the belief.

This is why, on the foundation of some tiny flaw in the evidence-the supposed lack of roof holes to admit poison-gas cans in one of the Auschwitz-Birkenau gas chambers for Holocaust deniers, the expectant faces on the grassy knoll for JFK plotters, the melting point of steel for 9/11 truthers-we go on to build a great edifice of mistaken conviction.

I say “we” because, after reading Mr. Shermer’s book and others like it, my uneasy conclusion is that we all do this, even when we think we do not. It’s not a peculiarity of the uneducated or the fanatical. We do it in our political allegiances, in our religious faith, even in our championing of scientific theories. And if we all do it, then how do we know that our own rational rejections of conspiracy theories are not themselves infected with beliefs so strong that they are, in effect, conspiracy theories, too?

There was a time, when I was younger, when I was confident that I knew how to tell a barmy belief from a rational deduction. I have lost some of that confidence.

This has been caused partly by the frequent experience of having friends who share my view on one issue but then suddenly reveal a view on another issue that is anathema to me. I don’t believe in ghosts, says a friend, but there is definitely something to homeopathy; or God does not run evolution, but the government should run the economy. Like me, Mr. Shermer is an economic conservative and a social liberal, so he encounters this dissonance a lot.

Mr. Shermer offers a handy guide for those who are confused. Conspiracy theories are usually bunk when they are too complex, require too many people to be involved, ratchet up from small events to grand effects, assign portentous meanings to innocuous events, express strong suspicion of either governments or companies, attribute too much power to individuals or generate no further evidence as time goes by.

Sure. But those are the easy cases. What about the harder ones?

Take climate change. Here is Mr. Shermer’s final diagnostic of a wrong conspiracy theory: “The conspiracy theorist defends the conspiracy theory tenaciously to the point of refusing to consider alternative explanations for the events in question, rejecting all disconfirming evidence for his theory and blatantly seeking only confirmatory evidence to support what he has already determined to be the truth.”

This describes many of those who strive to blame most climate change on man-made carbon dioxide emissions. Of course, they reply that it also describes those who strive to blame most climate change on the sun.

That’s how belief systems work: On both sides, there is huge belief, buttressed by confirmation bias, and equally huge belief that the belief and the conspiracy are all on the other side. Rick Perry, Al Gore-each thinks the other is a mad conspiracy theorist who will not let the facts get in the way of prejudices. Maybe both are right.