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Updated: November 16, 2013 17:31 IST
Armchair with a view

Rise of the fallacy

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Illustration: Satwik Gade
The Hindu
Illustration: Satwik Gade

Be informed, but beware of mistruths, says the author.

Scientists now claim that carbohydrates could be more addictive than cocaine. But regardless of what your personal preference of mind-altering substance is, if I were to tell you that crime in India has actually gone down in the last decade, would you believe me? Perhaps your eyebrows might elevate themselves in the manner of that epitome of rationality, Science Officer Spock from Star Trek. But what you should do as a good citizen is to verify this from the very excellent portal that makes everything from family welfare statistics to historical crime data available in a format any of your MBA-infected relatives should be able to process with a pirated copy of Microsoft Excel.

One of the good things about open data is that the average person can verify the kind of bovine ordure that often passes for insight and inference on TV news channels. The bad thing, however, is that with more data comes the potential for a whole new wave of fallacious analyses.

For instance, has crime gone up or has crime reporting gone up? Let’s say, hypothetically, that the jail occupancy numbers from 1953 to 2012 for the State of Andhra Pradesh show a steadily rising trend with a sudden drop in the 2000s, followed by a steady rise again. You can interpret this data in many ways. The opposition could say that this is symptomatic of continuously deteriorating governance. The Police could say that this is proof that they are getting better at catching criminals over time. The chap in charge of prisons in the State could say that it’s indicative of his department’s commitment to increasing jail capacity all the time. The government in power during that sudden drop in the 2000s could claim that it had a Sherlockspalli Holmesreddy whose magic wand pulled the inexorable crime rate line down. The opposition then could argue that it had nothing to do with better policing but the choice to migrate government computers from MS Office to Open Office, a move that resulted in improper use of spreadsheet software thus resulting in the alleged drop in crime. I could argue that the trend correlates directly to the quality of biriyani served in prisons and that the drop in 2000 is due to a change in caterer. And finally, someone with some common sense might even ask if jail occupancy, crime reporting and crime are different things altogether.

Another common fallacy in the way we interpret data is called the Texas Sharpshooter fallacy. Imagine a washed-up retired cowboy who has nothing better to do than to sit in his backyard and fire his gun at his barn’s wall randomly. Being quite a poor shooter, the bullet holes on the wall are all randomly spread out, except in a few places where the holes seem clustered together. Now, he goes and paints shooting targets centred around these clusters so that casual observers, looking at his barn’s wall, will infer that he is a brilliant sharpshooter.

This fallacy works because our brains are all inherently wired to look for patterns while ignoring noise. This ability was extremely useful for a long period in mankind’s history, especially when there were no Saravana Bhavans to order dosa from. Hunter gatherers had to make quick decisions based on pattern recognition to avoid becoming lunch for a larger predator. But in today’s world, this is a big problem because the ability to see the noise and ignore the illusion of a signal is pretty much the skill that will help you avoid becoming lunch for large predators like governments, companies and the news media.

When I was growing up, more kids were buying books about an obscure French apothecary named Michel Nostradamus than books about Statistics and Probability. Nostradamus’ fame was based on his alleged ability to “predict” world events before they occurred. There was, however, one small catch. His language (16 century poetic French) was so obscure that there was absolutely no way in which one could usefully predict something that has not happened yet. But one could unearth numerous patterns and hints that “proved” that he had predicted events that happened after his death but well before ours. He was a classic case of the sharpshooter fallacy in play. It’s very tempting for us to look at the few cases in which he seems to have got things right while completely ignoring a large proportion of what is essentially just questionable French poetry.

Incidentally, the sharpshooter fallacy is exactly how astrology works as well. A palm reader will tell you many things, including perhaps that one odd item that you felt was so true about yourself that you are willing to completely ignore all the incorrect stuff he told you. The very fact that a parrot could pick out your fortune should hint to you that it’s a combination of chance + sharpshooter fallacy.

The news, especially on TV, is riddled with this problem. What is largely anecdotal is what is passed off as analysis. Celebrity sound-bites are bizarrely used to lend credence to flawed analysis. Of course, this wasn’t a problem in the 1980s because Doordarshan spent more time letting us know that Giani Zail Singh did some ribbon-cutting at a foundation-stone-laying ceremony somewhere instead of passing off rare events as indicative of scary patterns, as the news does today.

So stop watching TV and read conflicting views and dig up real data about news stories before synthesising your own worldview. Getting all your news from TV is like snorting only cocaine in powdered sugar to get all your carbohydrates.


God of all thingsOctober 19, 2013

Celebs on my tableOctober 12, 2013

It’s all mayaOctober 5, 2013

The meat of the matterOctober 5, 2013

Avenues for apoplexySeptember 28, 2013

The browning versionSeptember 21, 2013

Bold leaps into the unknownNovember 10, 2013

Daily dose of delusionNovember 2, 2013

My thoughts about astrology and another sort known as "Naadi joshiyam"
are exactly the same.. A good satire and an extremely good analysis of
our brains' default. Oh That sherlockpalli holmesreddy is outright
hilarious; tiny bit racist, which adds to the humor. I am a big fan of
your column sir.Keep up the good work

from:  prashanth
Posted on: Nov 17, 2013 at 09:35 IST
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