Wednesday, October 11, 2006

I always knew this would happen, in hindsight anyway

I always knew that someone would eventually publish an article on the fallacy Postdiction, and I'd blog about it. The Washington Post - Iraq War Naysayers May Have Hindsight Bias - proves me right:

Antiwar liberals last week got to savor the four most satisfying words in the English language: "I told you so."

This was after a declassified National Intelligence Estimate asserted that the war in Iraq was creating more terrorists than it was eliminating. For millions of people who opposed President Bush's mission in Iraq from the start, this was proof positive that they had been right all along. Yes, they told themselves, we saw this disaster coming.

Only . . . that isn't quite true.

One of the most systematic errors in human perception is what psychologists call hindsight bias -- the feeling, after an event happens, that we knew all along it was going to happen. Across a wide spectrum of issues, from politics to the vagaries of the stock market, experiments show that once people know something, they readily believe they knew it all along.

Hence my inspiration for the addition of the fallacy Postdiction. More on hindsight bias:

This is not to say that no one predicted the war in Iraq would go badly, or that the insurgency would last so long. Many did. But where people might once have called such scenarios possible, or even likely, many will now be certain that they had known for sure that this was the only possible outcome.

….Baruch Fischhoff, a psychologist at Carnegie Mellon University and a pioneer in the field of hindsight bias, found that Americans who made estimates about their danger after the Sept. 11, 2001, attacks recalled having made much lower estimates of risk a year later, after their fears failed to materialize.

Fischhoff testified about psychological factors in judgment at a meeting of the House intelligence committee last week.

However, that's not to say having some idea of a potential poor outcome was impossible:

While hindsight bias in the context of the Iraq war was real, the psychologist cautioned in an interview against misuse of the idea -- the argument by many supporters of the Bush administration that it was impossible to know ahead of time how the war would turn out.

The real question to ask is were they in the 'position to know' that this was a potential outcome, and if so, did they make reasonable decisions along the way?


…people can fight the hindsight bias only when they honestly and systematically try to explain how different outcomes are possible. Such self-doubt is the exact opposite of how modern politics works: In the age of the blogosphere, certitude is king.

Without a doubt.