Heuristics and Bad Decisions

A perverse and often baffling fact about crime is that people are known to voluntarily confess to crimes they did not commit. I am not referring to coerced confessions – those times when a suspect is subjected to beatings or tricky interrogation techniques and admit guilt under duress. I have in mind the times when a person steps forward on his or her own volition to take the credit for a crime they had no part of. When Elizabeth Short was murdered in 1947, in what became infamously known as The Black Dahlia case, more than sixty people offered confessions. No fewer than 59 of those confessions were false. Likewise, a man named John Mark Karr was being held on child pornography charges when he claimed he murdered JonBenet Ramsey. His confession was rejected after it was found that his DNA did not match what was found on the scene and it was established that he was in another state at the time of JonBenet’s death.

It is a natural corollary that the higher profile the crime the more likely it is a false confession will be offered. In an effort to quickly weed out the false confessions and save themselves unnecessary legwork, the police will sometimes provide the press with false information. For example, if a sixty-year old stock broker is found dead in his den, strangled with a red scarf, the police might tell the press he was found in his kitchen, bludgeoned by a cast-iron skillet. Any person that comes into the police station and tells of how they killed this man with a cast-iron skillet is referred to a psychiatrist and promptly shown the door.

(It is at least theoretically possible that a guilty person could identify the false details of a case and then confess using those false details in order to lure the police into eliminating him as a suspect. When I first learned about this, I thought it would make a clever twist ending in a “Whodunnit?” murder mystery if it turned out the murderer was somebody who had come forward at the start of the film but gave a false false confession. To the best of my knowledge no one has ever tried that gambit in real life.)

Whether they realize it or not, the police are relying on a psychological shortcut known as a heuristic. Daniel Kahneman defines a heuristic as “a simple procedure that helps find adequate, though often imperfect answers to difficult questions.” Put another way, a heuristic is a rule-of-thumb strategy that enables us to make quick decisions or judgments by substituting a complex question with a simpler one. For example, when someone asks you, “How happy are you with your life these days?” you might substitute that question with, “What is my mood right now?” In the case of the false confession example above, the police are substituting the imprecise question, “Could this person be guilty?” with “Does this person know unpublished details about this crime?”

It may seem bizarre and unsettling, but we rely on heuristics in our day-to-day decision making as well as in how we formulate our attitudes. We rely on heuristics when we date, substituting questions like, “Are we compatible? Does he have good character?” with the question, “Am I attracted to him?” Similarly, when determining what our views ought to be about things such as gun control, we replace questions like, “What is the overall, long-term trend in gun crime?” with “When was the last time I heard about a school shooting?” We make hiring decisions by swapping out the question, “Will this person perform well in this career field, and is she qualified to work her?” with the question, “Did she shake my hand firmly when we met?

We rely on heuristics because our rational mind is lazy. Like detectives, we only have so much time, energy, and resources and we can’t chase down every possible lead. Answering a simple question reduces cognitive demand, but it bulldozes over many important factors and virtually all nuance. Asking, “Am I attracted to him?” ignores the fact that attractive men have less happy marriages and are more likely to cheat on their spouses. Likewise, if you are quick to recall a recent school shooting, you will likely overestimate the number of overall gun deaths and be less receptive of the research that shows gun crime has been dropping precipitously. On the other hand, if you cannot quickly recall a major gun crime, you run the risk of underestimating how severe the problem remains.

Heuristics are useful tools but they are prone to errors and they promote biases. It’s not a process we can actively turn off, but we can acknowledge that we are using them and that they influence our judgment. Kahneman suggests we constantly remind ourselves of this fact. Interviewers could remind themselves, he says, that “the question we face is whether this candidate can succeed. The question we seem to answer is whether she interviews well. Let’s not substitute.” We might findd ourselves ruling out a job applicant, a prospective spouse, or even a potential murderer based on these impressions. It would be healthy to stay openminded about some of these possibilities even after we’ve overlooked them. Kahneman reminds us, “you often have answers to questions that you do not completely understand, relying on evidence that you can neither explain nor defend.” Perhaps it would be helpful to our decision making to replace the word “no,” with “pending further investigation.”




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