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How science sorts fact from alternative fact

LiveMint logoLiveMint 25-04-2017 Faye Flam

You have the facts; now share them, reads an advertisement urging me to buy a gift subscription to Scientific American. Perhaps we’re seeing a backlash against Kellyanne Conway’s infamous “alternative facts”, or a response to fears that the US has entered a post-truth era. One way or another, facts have become a hotter commodity than coconut water and kale.

But how do any of us know for sure that the facts we believe are the real ones? Should you go with what your smartest friends post on social media? What you were taught in school? What the newspapers report? Wikipedia? The pages of Scientific American?

The bad news, scientists warn us, is that our brains are problematic places to seek reliable facts. In a new book titled The Enigma Of Reason, for example, the authors—two cognitive scientists—assert that humans use reason more often to bolster their existing ideas (and egos) than to find the truth. In another recent book, The Knowledge Illusion, cognitive scientists Philip Fernbach and Steven Sloman show how most people think they know much more than they actually do.

Princeton University psychologist Daniel Kahneman was a pioneer in cataloguing the glitches in human thinking. When I got a chance to talk to him about facts last month, he said we humans tend to think we’re basing our beliefs on solid evidence when we’re really just cherry-picking anecdotes or plain telling stories to support our existing beliefs.

This poses a puzzle. If humans have so much trouble gazing past our navels, how have we managed to learn so much about the origin of our species, the birth of our planet, and the infancy of the cosmos? Perhaps there’s something about the scientific method that helps us transcend the misleading tendencies of the human mind.

This seemed like a question for a philosopher of science, so I called Tim Lewens of Cambridge University, author of The Meaning Of Science. His answer was encouraging for seekers of truth, though it might surprise students of science.

He said there’s no universally agreed-upon definition of the scientific method. “It’s hard to come up with a categorization of the scientific method that fits with all the sciences and nothing but the sciences.” One standard definition says the scientific method consists of “systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.” But not all scientists agree. Different fields have come up with different methods—such as the use of certain statistical tests, or X-ray crystallography, or injecting drugs into mice. Some scientists only work in the realm of theory.

Over time, science has become more modest in its promises, said Lewens. After Isaac Newton formulated his laws, scholars thought his physics was the absolute truth and that the world couldn’t possibly work any other way. Then Einstein came along and burst the bubble with relativity, which better conforms to experimental tests and offers a different understanding of the nature of space, and gravity.

Scientists rarely talk about facts—a word that implies something immutable. They talk about measurements, which are subject to error and open to interpretation, and theories, which are provisional and therefore amenable to upgrades or wholesale revision. To many, it feels self-evident that science is progressing towards truth, even if we’re not there yet or may never get there.

The belief that science is approaching truth is called scientific realism, Lewens said. Not everyone subscribes to it—some philosophers and even a few scientists think new scientific ideas are useful but not necessarily steps towards a larger truth. But Lewens counts himself as a scientific realist, because in so many areas new ideas do build on or refine earlier ones. Science does seem to be getting somewhere.

And while lots of studies point to human fallibility, that doesn’t preclude our ability to do good, truth-seeking science. “It’s a presupposition of these studies that at least some of us can get the right answer some of the time,” he said. The right answer takes slower, more effortful thinking.

This kind of thought is what Kahneman describes in his book Thinking, Fast And Slow. For some people, the slower thinking system is on permanent vacation, but science is a group endeavour and some people in any field are likely to employ those more careful, smarter, slower modes of cognition.

Kahneman told me he believes the methods of science do nudge people to put the evidence first, ahead of their preconceived ideas. But there is no single method for doing this. He said different methods of doing science sometimes lead people to different conclusions—or if they are dogmatic enough, different facts.

Such alternative facts are striking in cosmology, where there’s now a controversy about how fast the universe is expanding. Some astronomers using supernova explosions as a measuring system get one answer, while others using microwaves from the big bang arrive at another.

What makes the astronomers’ alternative facts different from Kellyanne Conway’s is that the scientists on both sides used legitimate methods to arrive at their conclusions, and they all recognize that someone must have it wrong. If coming up with an inaugural crowd estimate were a game like guessing the number of jelly beans in a jar, then Conway could have offered an alternative guess—not an alternative fact. Bloomberg

Faye Flam is a Bloomberg View columnist. -

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