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Why We Deceive Ourselves (Sometimes)
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What Is Skepticism, Anyway?

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As the publisher of Skeptic magazine I am often asked what I mean by skepticism, and if I'm skeptical of everything or if I actually believe anything. Skepticism is not a position that you stake out ahead of time and stick to no matter what.

Consider global warming: Are you a global warming skeptic? Or are you skeptical of the global warming skeptics? In this case, I used to be a global warming skeptic, but now I'm skeptical of the global warming skeptics, which makes me a global warming believer based on the facts as I understand them at the moment. The "at the moment" part is what makes conclusions in science and skepticism provisional.

Thus, science and skepticism are synonymous, and in both cases it's okay to change your mind if the evidence changes. It all comes down to this question: What are the facts in support or against a particular claim?

There is also a popular notion that skeptics are closed-minded. Some even call us cynics. In principle, skeptics are neither closed-minded nor cynical. We are curious but cautious.

Or, I often hear, "Oh, you're a skeptic, so you don't believe anything?" No, I believe lots of things, as long as there is reason and evidence to believe. For example:

• I believe in the germ theory of disease.

• I believe that vaccines are good for societal health.

• I believe that fluoridated water reduces cavities.

• I believe in the Big Bang theory of the universe.

• I believe that the theory of evolution best explains life.

• I believe that the theory of plate tectonics best explains the the continents.

• I believe that the periodic table of elements best explains chemistry.

• I believe that JFK was assassinated by a lone gunman named Lee Harvey Oswald.

• I believe aliens are probably out there somewhere but that they have not visited Earth.

Being a skeptic just means being rational and empirical: thinking and seeing before believing. The Oxford English Dictionary gives this historical usage of the word Skeptic:

"One who doubts the validity of what claims to be knowledge in some particular department of inquiry; one who maintains a doubting attitude with reference to some particular question or statement." And: "A seeker after truth; an inquirer who has not yet arrived at definite convictions."

I often hear, "Oh, you're a skeptic, so you don't believe anything?" No, I believe lots of things, as long as there is reason and evidence to believe. - Michael Shermer

Skepticism is not "seek and ye shall find," but "seek and keep an open mind." But what does it mean to have an open mind? It is to find the essential balance between orthodoxy and heresy, between a total commitment to the status quo and the blind pursuit of new ideas, between being open-minded enough to accept radical new ideas and so open-minded that your brains fall out. Skepticism is about finding that balance. Here is a definition of skepticism:

Skepticism is the rigorous application of science and reason to test the validity of any and all claims.

Skeptics question the validity of a particular claim by calling for evidence to prove or disprove it. In other words, skeptics are from Missouri -- the "Show Me" state. When we skeptics hear a fantastic claim, we say, "That's interesting, show me the evidence for it."

You say you believe in Big Foot? I say, "That's interesting, show me a body of a Big Foot creature and I'll believe."

You say you believe that aliens have landed on Earth? I say, "That's fascinating, show me an alien body or a crashed spacecraft and I'll believe."

It is not always easy to evaluate claims, and so we skeptics have developed what the astronomer Carl Sagan called "the fine art of baloney detection." Inspired by Sagan, at Skeptic magazine we produced what we call the Baloney Detection Kit, which consists of a list of questions to ask when encountering any claim. Here are a few:

Does the source of a claim often make similar claims? Pseudoscientists have a habit of going well beyond the facts, so when individuals make numerous extraordinary claims they may be more than just iconoclasts.

Have the claims been verified by another source? Typically pseudoscientists will make statements that are unverified, or verified by a source within their own belief circle. We must ask who is checking the claims, and even who is checking the checkers? The biggest problem with the cold fusion debacle, for example, was not that Stanley Pons and Martin Fleischman were wrong; it was that they announced their spectacular discovery before it was verified by other laboratories (at a press conference no less), and, worse, when cold fusion was not replicated they continued to cling to their claim.

Has anyone gone out of the way to disprove the claim, or has only confirmatory evidence been sought? This is the confirmation bias, or the tendency to seek confirming evidence and reject or ignore disconfirming evidence. It is why the methods of science that emphasize checking and rechecking, verification and replication, and especially attempts to falsify a claim, are so critical.

Has the claimant provided a different explanation for the observed phenomena, or is it strictly a process of denying the existing explanation? This is a classic debate strategy -- criticize your opponent and never affirm what you believe in order to avoid criticism. But this stratagem is unacceptable in science. Big Bang skeptics, for example, ignore the convergence of evidence of this cosmological model, focus on the few flaws in the accepted model, and have yet to offer a viable cosmological alternative that carriers a preponderance of evidence in favor of it.

Do the claimants' personal beliefs and biases drive the conclusions, or vice versa? All scientists hold social, political, and ideological beliefs that could potentially slant their interpretations of the data, but how do those biases and beliefs affect their research? At some point, usually during the peer-review system, such biases and beliefs are rooted out, or the paper or book is rejected for publication. This is why one should not work in an intellectual vacuum. If you don't catch the biases in your research, someone else will.

Also in the Skeptics' Toolkit is an aphorism often attributed to Carl Sagan, but was actually said by others before and in several different wordings, but regardless of its etymology this is a line you should keep in mind whenever someone regales you with an extraordinary claim:

Extraordinary claims require extraordinary evidence

That is, the more fantastical the claim, the more skeptical you should be unless the evidence is equally fantastic.

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