Did You Know It All Along?: The Psychology of Hindsight Bias

Who will win the presidency in 2012? Will it be Obama or Romney? It's mid October 2012, and no one can say. Sure, there are pundits aplenty with precise predictions, who speak as though they know exactly what the future portends but in reality are simply parroting a party line. For the rest, of course, it is all too clear that we just don't know. There are no crystal balls, and no one can foresee the future. In fact, there has probably not been such a moment of such perfect uncertainty since the start of the election season. Back in September Obama had an edge, but in recent weeks Romney appears to have closed the gap. This uncertainty opens the doors of our imagination: we can visualize what another Obama or a new Romney presidency might be like, we can speculate this way and that, we can let our imaginations run wild. But in the end we just don't know. We are uncertain. On November 6, 2012, that uncertainty will vanish and we will all finally know for sure.

Here's an interesting aspect of the way our minds deal with future and past. Once we all know the answer -- who is going to be president for the next four years -- this current feeling of uncertainty, the current "not knowing," will not only disappear (once we know what is so), but it will also become oddly, uncannily difficult to remember. We will look back upon these days and feel as though we knew it all along.

Psychologists call this "hindsight bias," and it is among the most widely studied of decision traps. According to a recent scholarly review that we co-authored, some 800 scientific papers have looked at hindsight bias since it was first brought to light in the 1970s. Hindsight bias is usually a matter of degree. Before something happens, you might think an event somewhat likely (like a 60 percent chance) but then after, as you look back on those events, you inflate your certainty somewhat (seeing it now as very likely, like an 80 percent chance).

Hindsight bias makes our memory of the past seem solid, knowable, and more predictable than it actually was when we lived through that past. So, in a year's time, you may look back at the news events of right now, at your conversations and speculations with friends and family, at the performances during the presidential and vice-presidential debates of October 2012 and think to yourself: "Oh sure, I could see the writing on the wall: I just knew X would win the election."

Psychological research shows that hindsight bias is a product of the normal workings of human memory. When we learn something new, we immediately connect it to other, related knowledge stored in memory. As we make those connections, the facts we know strengthen one another. The more that we see things fitting together, the more we feel as though we knew it all along. Psychologists have studied hindsight bias since the 1970s because it harms people's ability to make sound decisions.

Take the example of a manager looking for the cause of a recent drop in sales. She might settle on a single explanation -- say, the performance of one particular employee -- and become very certain that it's all the fault of that one employee, because he could have been more attentive to sales patterns back when swift intervention might well have saved the day. Hindsight bias means paying less attention to alternative explanations and different lines of evidence. It means sticking to a single explanation and failing to dig deeper. And it often means blaming others more than they ought to be blamed, simply because you feel like the causes of failure are obvious after the fact. Hindsight bias, at its root, is an oversimplification of the past and a scrubbing away of prior uncertainty, doubt and complication.

Years of research have found hindsight bias to be tough to fix. It's hard to think your way out of it but, at the very least, you might become more aware of it. Right now, you might study and maybe even savor your uncertainty of who will be our next president. If you are like most people, that uncertainty will soon evaporate into the mists of your memory, right after the results are revealed on election night. But with some attention, care, and practice, you might start to see hindsight bias afflicting your own thinking. And if you happen to be reading this after November 6, 2012, then none of this may make the slightest sense to you, because you knew who would be the next president all along.

Neal Roese is a social psychologist who teaches at the Kellogg School of Management, Northwestern University. Kathleen Vohs is a social psychologist who teaches at the Carlson School of Management, University of Minnesota.

Roese and Vohs are the authors of "Hindsight Bias," a scholarly review article appearing in the current issue of Perspectives on Psychological Science.