US FOREIGN POLICY WEEK 1 REFLECTION 2
1/16/2019 Be Forewarned: Your Knowledge is Decaying
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DECISION MAKING
Be Forewarned: Your Knowledge is Decaying by Samuel Arbesman
NOVEMBER 05, 2012
When was the last time you read one of your old textbooks? I bet it’s been awhile. But if you were to
compare the version you studied in school to the most recent edition currently in use — no matter
how recently you graduated — you’d find your version sorely outdated. You shouldn’t be surprised
by this: facts are changing all around us.
Whether it’s what we think is true — the nutritious value of certain foods, the status of Pluto as a
planet, or the number of chromosomes in a single human cell — or even the state of our
surroundings — the population of the planet, the fastest 100-meter dash, or the powers of particle
accelerators — our knowledge is in constant flux.
It turns out knowledge is a lot like radioactive atoms because it decays over time. And when we’re
dealing with large amount of facts and information, we can actually predict how long it will take for
it to spread or decay by applying the laws of mathematics. In fact, there’s even a field of science
called scientometrics that studies such things from a quantitative perspective. We now know that
there is a shape to how knowledge grows and how it spreads through a population. We can also
examine different branches of knowledge — medicine, sociology, etc. — and see how long it takes for
half of what we know in these fields to be overturned or rendered obsolete. For example, in the
fields of hepatitis and cirrhosis — medical fields related to diseases of the liver — researchers have
found that half of the knowledge was overturned in about 45 years.
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Of course, some of what we learn will probably never change in our lifetime, such as the number of
continents. And some will change often, such as the number the stock market closed at yesterday.
But those aren’t the facts we should be worried about. We should be concerned most about the facts
that change slowly, the facts that change over the course of years or decades or an entire lifetime —
these are called mesofacts — and examples include everything from the populations of cities to what
dinosaurs looked like (they had feathers?).
We need to recognize that mesofacts are far more common than we may realize — but it’s not easy. In
hindsight they may seem obvious, but they’re not. Since mesofacts decay very slowly, we often fail
to recognize their change around us. This is a problem.
A friend of mine, for example, was speaking recently with an older hedge fund manager who began a
story with the following: “Since we all know that there are 4 billion people on the planet…” This is a
problem. This finance expert is dead wrong — in fact, he’s billions of people off (we’re now over
seven billion). His information is several decades out of date. Now imagine if he were making
decisions based on this information. It wouldn’t be good.
This may be an extreme example, but people make all kinds of decisions based on outdated facts all
the time. Just think about demographics. How many marketers and advertisers have failed to keep
up with the shrinking percentage of Caucasians in the United States? Probably a lot.
While it’s okay to quote some half-remembered fact you read in a magazine years ago at a party,
using it as a basis for a decision can have profound consequences. And this is only becoming a bigger
problem as the information around us grows faster and changes more quickly.
Unfortunately, there’s no easy way to remain cognizant of the changes. But we must admit to
ourselves that a large fraction of what we learn is going to be obsolete within a few years — as
medical school students are taught — so we can take a healthier approach to decision making.
We need to constantly reeducate ourselves, avoid memorization, and start looking up facts to make
sure that we have the most updated knowledge. We need to incorporate an informational humility
into our lives. Otherwise, we’ll be stuck selling buggy whips to car owners. Or making maps that
show the wrong number of planets.
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Samuel Arbesman is Scientist in Residence at Lux Capital. He is also a Senior Fellow of the Silicon Flatirons Center
of Law, Technology, and Entrepreneurship at the University of Colorado and a Research Fellow at the Long Now Foundation.
He is the author of Overcomplicated: Technology at the Limits of Comprehension. He is @arbesman on Twitter.
Related Topics: KNOWLEDGE MANAGEMENT
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