Who’s afraid of evidence?

Astrophysicist Neil deGrasse Tyson recently tweeted:

Earth needs a virtual country: #Rationalia, with a one-line Constitution: All policy shall be based on the weight of evidence

Apart from theocrats and dictators, you’d think most everyone could agree with that sentiment in principle. But not UCLA sociologist Jeffrey Guhin: he says it’s “a very stupid idea”. Guhin, you see, has uncovered a fatal flaw in the scientific method (brace yourself): Scientists aren’t perfect!

… experts usually don’t know nearly as much as they think they do. Experts often get it wrong, thanks to their inherently irrational brains that, through overconfidence, bubbles of like-minded thinkers, or just wanting to believe their vision of the world can be true, mislead us and misinterpret information. Rationality is subjective. All humans experience such biases; the real problem is when we forget that scientists and experts are human too—that they approach evidence and reasoned deliberation with the same prior commitments and unspoken assumptions as anyone else. Scientists: They’re just like us.

Well, that’s a surprise to precisely no one. Apart from the “rationality is subjective” nonsense, scientists would certainly agree with the above, Tyson included. That’s why the scientific method has developed tools to help correct for error and minimize bias: randomized and blinded experiments, peer review, meta-analysis, etc. Which is how, despite the human flaws of individuals scientists, science has been so amazingly successful at expanding our knowledge and improving our lives: electromagnetism, evolution, genetics, cosmology — the list goes on and on. Advances in medical science have doubled our life expectancy over the last century. Guhin, however, is not impressed:

… science has no business telling people how to live. It’s striking how easily we forget the evil following “science” can do. So many times throughout history, humans have thought they were behaving in logical and rational ways only to realize that such acts have yielded morally heinous policies that were only enacted because reasonable people were swayed by “evidence.” Phrenology—the determination of someone’s character through the shape and size of their cranium—was cutting-edge science. (Unsurprisingly, the upper class had great head ratios.) Eugenics was science, as was social Darwinism and the worst justifications of the Soviet and Nazi regimes. Scientific racism was data-driven too, and incredibly well respected. Scientists in the 19th century felt quite justified in claiming “the weight of evidence” supported African slavery, white supremacy, and the concerted effort to limit the reproduction of the lesser races…

And yet, despite its abysmal track record, people continue to have extremely positive opinions of “science.”

You’ve got to be kidding me: “abysmal track record”!? Just last week, NASA’s spacecraft Juno entered Jupiter’s orbit after travelling 1.7 billion miles over five years — and it arrived within one second of the predicted time. Now, it’s true that following the scientific method does not guarantee immunity from mistakes: reality is complicated. But Guhin’s purported examples of “the evil following science can do” are actually not scientific at all: from pseudoscience (like phrenology) to fascistic propaganda (like Nazism), the great mistakes of history were caused by ideological dogmatism, and would have been prevented by more skepticism and more insistence on rational evaluation of the evidence — exactly the lesson Tyson wants us to learn. Sure, the bad guys tried to leech off science’s good reputation by claiming it was on their side, but saying something is scientific doesn’t make it so. Does Guhin think Scientology is a scientific organization? Does he consider North Korea a democracy just because it calls itself “the Democratic People’s Republic of Korea”?

Democracy is actually a good example of another system we stick with even though it’s imperfect — because it’s better than the alternatives. And that is the crux of the matter. Science is hard, and we should do our best to understand the ways it can fail so as to mitigate them; but come decision time, the only relevant question is whether there’s a superior alternative. If experts and evidence are stupid, what does Guhin think we should base our policy on instead? What method has a better track record than science? He does not get very specific about that.

Science may give us data, but that doesn’t mean that data points to truth—it just means that’s what we currently understand as truth. So how we act on that data requires nuance and judgment. It’s philosophical, maybe religious, and certainly political.

Oh, we just need to use “nuance and judgement”! Genius. What else? “Maybe religious,” he says — but which religion would that be? There are many, their prescriptions usually conflicting. And since religious beliefs aren’t evidence-based, religious differences cannot be resolved through rational discourse (witness the wonderful policies of ISIS, for instance). As for philosophy and politics, I would hope those are based on reason and evidence — otherwise we’re just back to religion again. Evidence is what grounds us to reality, and losing touch with reality inevitably turns out badly. Science is no more and no less than our best honest attempt to figure out what’s really true about the world we live in — and that’s exactly what you want to base your life decisions on.

Why, then, is Guhin so irrationally opposed to Rationalia? I don’t know. Perhaps he’s afraid that if the demand for reasonable arguments supported by evidence ever becomes widespread, he’ll have a hard time getting published.