Matt Ridley: The perils of confirmation bias - part 3

Climate science needs gadflies

I argued in my last column that the way to combat confirmation bias-the tendency to behave like a defense attorney rather than a judge when assessing a theory in science-is to avoid monopoly. So long as there are competing scientific centers, some will prick the bubbles of theory reinforcement in which other scientists live.

For constructive critics, this is the problem with modern climate science. They don't think it's a conspiracy theory, but a monopoly that clings to one hypothesis (that carbon dioxide will cause dangerous global warming) and brooks less and less dissent. Again and again, climate skeptics are told they should respect the consensus, an admonition wholly against the tradition of science.

Matt Ridley: The perils of confirmation bias - part 2

What keeps scientists accurate is rivals' scepticism, not their own

If, as I argued in the first of these columns, scientists are just as prone as everybody else to confirmation bias to looking for evidence to support rather than test their ideas ­ then how is it that science, unlike cults and superstitions, does change its mind and find new things?

The answer was spelled out by the psychologist Raymond Nickerson of Tufts University in a paper written in 1998: "It is not so much the critical attitude that individual scientists have taken with respect to their own ideas that has given science the success it has enjoyed... but more the fact that individual scientists have been highly motivated to demonstrate that hypotheses that are held by some other scientist(s) are false."

Matt Ridley: The perils of confirmation bias - part 1

How scientists collect positive evidence rather than test theories: There's a myth out there that has gained the status of a cliché: that scientists love proving themselves wrong, that the first thing they do after constructing a hypothesis is to try to falsify it. Professors tell students that this is the essence of science.

Yet most scientists behave very differently in practice. They not only become strongly attached to their own theories; they perpetually look for evidence that supports rather than challenges their theories. Like defense attorneys building a case, they collect confirming evidence.