I knew it all along . . . beware of hindsight bias
Posted on February 4, 2012
Hindsight bias: our tendency to reconstruct the past to fit with present knowledge. Also known as Monday morning quarterbacking. After the event, we look back to reconstruct how it happened, why it had to happen that way, and how we should have seen it coming all along. Under the influence of this bias, improbable and unpredictable events become not only probable but practically certain after they happen. Recall the o-ring Challenger explosion and the Columbia foam strike to the wing, both studies in hindsight bias. Think also of the pre-9/11 memo warning Bin Laden could strike in the U.S. In the aftermath, many concluded that we should have seen it coming all along, that it was inevitable. But was it?
Like these notorious historical examples of hindsight bias, lawsuits also involve reconstruction of history, an attempt to assemble a credible, accurate picture of past events. What happened? Who did what to whom? What motives drove the parties to act? Every case also involves forward-looking strategic and tactical decisions for the lawyers based on incomplete information and uncertainty about outcome. In both instances – attempting to determine historical fact and assessing outcomes – lawyers succumb to hindsight bias. First, when we look back to the events leading to the controversy, we often construct our view of the facts by reverse engineering: we focus on the outcome and string together a series of putatively causal facts to make the resulting event seem certain. This often undergirds the theory of legal responsibility for the outcome by allowing us to impute this same 20/20 retrospection to one of the parties in the dispute. This leads to many forms of casual misattribution, including post hoc ergo propter hoc (after that, because of that), reverse causation (not A caused B, but B caused A), joint causation (A and B caused C), and failure to consider alternative causes (more on these causal erros in later posts).
The hindsight bias thus reinforces preconceived notions and relates to the confirmation bias (see February 2, 2012 post). This same bias leads us to evaluate the outcome in ways that make that ending appear as if no other result could have happened. We attribute causal necessity to unpredictable litigation events in a manner that short circuits our ability to learn from our mistakes. We are then more inclined to repeat our past mistakes.
Guard against the hindsight bias by always seeking alternative causal explanations and by respecting the inherent uncertainty – if not randomness – in many events.