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Saturday, February 01, 2020

The tough life of a skeptic

A crash course in how to think rationally about complex scientific questions

I n my thirty years of doing research, I've seen a lot of bad science. I've seen colleagues publish data they knew to be misleading. I've seen directors pressuring junior employees to publish things they knew were false. I've seen scientists happily write papers, one after another, on theories they knew to be dead ends.

This showed me how weak data often are, and how the ambitious sometimes get fixated on theories that are totally wrong, sometimes wasting their entire career believing in an idea that is just too good not to be true. They may even convince their colleagues to follow their blind alley.

This is why skepticism is so important. Individual failings waste time and resources, but on average they'll cancel each other out. But scientific fads, in which many people go down the same wrong path, mislead generations.

School of fish
There's safety in numbers, but which way to go? Image by Gordon Firestein - Seacology USA, CC BY-SA 3.0. Source

There have been many fads in science: cholesterol causes heart disease, frontal lobotomies can treat mental disorders, everybody should be on statins, vitamin C cures the cold, burgers made from soybeans taste exactly like real ones. At one time millions of people believed each of those things. Well, maybe not that last one. Nobody is that credulous.

It might be hard to believe now, but disagreeing with those fads was very difficult. The doctor who invented the lobotomy won the Nobel Prize for it. The scientist who made the claims for vitamin C won two of them. And who would dare argue with the nutty person who invented the veggie burger?

Fads happen when we uncritically accept some finding just because everyone else believes it. When that happens, the believers often make catastrophic mistakes. The challenge for the skeptic is not to know that experts can be wrong—though they often are—but to learn how to identify a fad.

How to identify a fad

A fad is a false belief held by a crowd. The goal of the faddist is to make people believe things that conflict with what they see. One way is to inundate readers with news purportedly caused by the event, for instance that X is doing Y, Z, A, B, and C. It's a trap: if the reader counters by saying X doesn't do Y, it solidifies in their mind that X exists, which is the faddist's real objective.

Another trick is an argument to authority. Some assertion is presented as a fact that was established by experts a long time ago. The experts could be charismatic individuals, a group of scientists, or a religious figure. If the authority said it, it must be true. This is a concealed threat: if you disagree with the authority, you are too unworthy or too stupid to understand the argument.

Other red flags are mocking and name-calling, which are ways of threatening you with social exclusion, and acts of emotional blackmail such as outrage or crying. Obscure jargon also works: it wears down your resistance by making you wish you were dead, and convinces you you're stupid if you can't follow the reasoning. Computer models are like jargon but use math instead of words, and they're also authority figures. Computers cannot lie; therefore the claim must be true.

Another tactic is to stampede people by creating a sense of urgency—action is needed now, you must panic now! We can't wait until the evidence is in!!! The skeptic should ask: how do you know that? And where did you buy all those exclamation points? Were they on sale?

This we-must-panic-now argument is called the precautionary principle, and it contradicts the claim that the science is settled.

These are logical fallacies that the faddist uses to get falsehoods accepted by the crowd. These days being a skeptic is a full time occupation, but look at the bright side: it's a target-rich environment.

Skepticism in science

Many people are totally confused about skepticism. They think skepticism is only legitimate for themselves, but not for others. Here's an example:

Scientific skepticism is healthy. Scientists should always challenge themselves to improve their understanding. Yet this isn't what happens with climate change denial. Skeptics vigorously criticise any evidence that supports man-made global warming and yet embrace any argument, op-ed, blog or study that purports to refute global warming.

This article has more red flags than Tiananmen square on Mao's birthday. He's saying, in effect, that skepticism about his position is illegitimate. Later in the article he talks about “killer hurricanes, devastating wildfires, melting glaciers, and sunny-day flooding in more and more coastal areas around the world,” and claims that any skepticism is funded by oil companies. Whether these purported facts are true or not isn't relevant to us here. What's relevant is that this person evinces no skepticism about his own beliefs. Despite his protestations of scientific objectivity, he is no skeptic.

Calling a skeptic a denier is an example of the question-begging (petitio principii) fallacy: it assumes the truth of the conclusion. Denial is only culpable if what you're denying is undeniably true. Skeptics have the right to question any aspect of your argument, including challenging your evidence. How do you know your measurements were correct? Could there be a confounding factor that explains your results? How do we know your error prop calculations are correct? Did you even do error prop? Where's the source code for your model? What happened to all the original records, and why are bits of paper hanging out of your dog's mouth? These questions may be annoying, but they are all legitimate. If you don't answer them, the skeptic is justified in con­clud­ing you can't. It's a corollary to Godwin's Law: when the claimer calls the skeptic a denier, the skeptic has won the argument.

It is also an ad hominem argument. Often you're assuming your opponent actually does believe your claim, but is pretending to doubt you for some sinister reason: someone is paying them, or they are merely being political.

Being skeptical requires courage. You will lose friends and social status. When the crowd changes direction, they will forget you were the one who warned them. But for a scientist, skepticism can save years of wasted effort. A skeptic recognizes that evidence is almost always shakier than it looks. No theory is perfect, and good scholarly practice means you must cite the evidence against your claim as well as that which favors it. If nothing else, skeptics help with that.

Contrary to what many people think, being skeptical also means being open to ideas. Skepticism isn't a weapon to shoot down viewpoints with which you disagree. It's an effective way of finding the truth. We must be as skeptical about our own ideas as about others': it's better to find your own mistake before someone else finds it. A true skeptic will consider any idea, provided it is well reasoned and backed up with evidence. And then, armed with an understanding of its weaknesses, tear it to shreds.

feb 01 2020, 6:33 am

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