Cities & Communities
By Michael Shermer in The New Scientist
WHAT is the difference between a sceptic and a denier? When I call myself a sceptic, I mean that I take a scientific approach to the evaluation of claims. A climate sceptic, for example, examines specific claims one by one, carefully considers the evidence for each, and is willing to follow the facts wherever they lead.
A climate denier has a position staked out in advance, and sorts through the data employing “confirmation bias” – the tendency to look for and find confirmatory evidence for pre-existing beliefs and ignore or dismiss the rest.
Scepticism is integral to the scientific process, because most claims turn out to be false. Weeding out the few kernels of wheat from the large pile of chaff requires extensive observation, careful experimentation and cautious inference. Science is scepticism and good scientists are sceptical.
Denial is different. It is the automatic gainsaying of a claim regardless of the evidence for it – sometimes even in the teeth of evidence. Denialism is typically driven by ideology or religious belief, where the commitment to the belief takes precedence over the evidence. Belief comes first, reasons for belief follow, and those reasons are winnowed to ensure that the belief survives intact.
Denial is typically driven by ideology or religious belief, where the belief takes precedence over evidence
Denial is today most often associated with climate science, but it is also encountered elsewhere. For example, there are those who do not believe that HIV causes AIDS. Others say that the Holocaust did not happen, or reject the overwhelming evidence for evolution. All merit the moniker “denier”, because no matter how much evidence is laid out before them they continue to deny the claim.
Though the distinction between scepticism and denial is clear enough in principle, keeping them apart in the real world can be tricky. It has, for example, become fashionable in some circles for anyone who dares to challenge the climate science “consensus” to be tarred as a denier and heaved into a vat of feathers. Do you believe in global warming? Answer with anything but an unequivocal yes and you risk being written off as a climate denier, in the same bag as Holocaust and evolution naysayers.
Yet casting questions like these as a matter of belief is nonsensical. Either the Earth is getting warmer or it is not, regardless of how many believe it is or is not. When I say “I believe in evolution” or “I believe in the big bang”, this is something different from when I say, “I believe in a flat tax” or “I believe in liberal democracy”.
Either evolution and the big bang happened or they did not; both matters can, in principle, be solved with more data and better theory. But the right form of taxation or government cannot be answered with more data and better theory. They are ideological positions that are established by subjective debate. Liberals committed to one vision of society will marshal evidence to support their political beliefs, while conservatives buttress their own world view. Both sides are sceptical of each other’s position, both deny information that contradicts their own views, and in most cases disputes are resolved not through experiment and hypothesis testing but through democratic election.
What sometimes happens is that people confuse these two types of questions – scientific and ideological. Sometimes the confusion is deliberate. Denial is one outcome. Thus, one practical way to distinguish between a sceptic and a denier is the extent to which they are willing to update their positions in response to new information. Sceptics change their minds. Deniers just keep on denying.
Read more: Special report: Living in denial
In a nutshell: Global warming either (1) isn’t real (2) isn’t caused by humans or (3) doesn’t matter
Origin: Corporate astroturfing in the early 1990s
Call themselves: Climate sceptics
In a nutshell: The theory of evolution is an atheist conspiracy to undermine religion
Origins: 19th century, though continually renewed
Call themselves: Creationists or intelligent design advocates
In a nutshell: The systematic mass killing of European Jews by Nazi Germany is a fabrication, or at least a wild exaggeration
Origins: Late 1940s
Call themselves: Holocaust revisionists
In a nutshell: HIV either (1) does not exist or (2) does not cause AIDS
Origins: 1987, when molecular biologist Peter Duesberg of the University of California questioned the link between HIV and AIDS in an academic paper
Call themselves: AIDS truthers
In a nutshell: The US government either orchestrated or was complicit in the 9/11 attacks
Origins: Doubts about the official version of events were circulating within days of the attacks
Call themselves: 9/11 truth movement
In a nutshell: Umbrella term for a disparate movement claiming that certain vaccines either (1) do not work or (2) are harmful
Origins: Has been around for as long as vaccines
In a nutshell: There is considerable uncertainty about the science linking tobacco smoke to lung cancer
Origin: 1970s, tobacco industry
Michael Shermer is the publisher of Skeptic magazine, a columnist for Scientific American, an adjunct professor at Claremont Graduate University in California and the author of Why People Believe Weird Things, Why Darwin Matters and The Mind of the Market. His next book is The Believing Brain