Sep 22, 2011

Mind Reading: Why Bad Math Can Ruin Your Health

“How do we know which numbers to trust and which health studies are sound? Healthland faces this dilemma every day, so we spoke with Charles Seife, the rare journalist with an undergraduate degree in mathematics, from Princeton no less. In his book Proofiness: The Dark Arts of Mathematical Deception, Seife explores the common ways math can be used to mislead people.

What is “proofiness”?
It’s the art of using math to tell untruths, the art of using bogus numbers or numbers that are semi-right to mislead.
One example I like is when Quaker Oats had a huge ad campaign to try to convince people that eating oatmeal could lower cholesterol dramatically. It put a graph on the back [of the package] that showed a dramatic decline in cholesterol levels. And there was a drop, according to a study. But if you look carefully, the Y-axis was manipulated so that a really very tiny drop looked huge, when in fact, there was only a few points [decline] out of 200.

And what is the phenomenon you call “randumbness”?
We humans have a hard time recognizing that things can actually have no [discernible] cause. They are random. The roll of the dice isn’t influenced by external factors [like wearing your lucky shoes]. That’s how Las Vegas makes all its money. People think that if they’re winning, they should keep doing [what they're doing]; if they’re losing they’re due to win soon. The universe doesn’t care whether you win or lose — things are just random.

So, it’s the fallacy that comes when we think something is [causally connected to something else], when in fact there’s no cause behind it. I like to link it to what I call cause-uistry — what happens when, say, there is a cancer cluster or you spot a group of people who have more than the expected number of a certain type of cancer. It may be that there’s a toxin or something causing it. But by the sheer fact that you are looking at the entire country, of course there are going to be some places where there is a more-than-average incidence of cancer. Just through random chance, in some places there will be an increase in cancer, and in some places it will be lower than expected.

So cause-uistry is a glib name for the fallacy that correlation equals causation. Just because two things seem to be related doesn’t mean that one affects the other. [Still] our brains lead us to connect things even if they are not connected. One fun example: when I was doing reporting on something else, a member of Congress tried to pitch me on building more power plants. He said that if you increase power production, then infant mortality drops. It’s true. It’s also true that when Internet use goes up, infant mortality drops. And car driving. Of course, those are all symptomatic of a high-tech society that has good health care.”

Read more at Time Healthland

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