It’s good to have Gladwell back. I’ve missed his writing these last few months. (To learn about his next book, check out Kottke.) His article this week was on the (pseudo)science that is criminal profiling:
In the case of Derrick Todd Lee, the Baton Rouge serial killer, the F.B.I. profile described the offender as a white male blue-collar worker, between twenty-five and thirty-five years old, who “wants to be seen as someone who is attractive and appealing to women.” The profile went on, “However, his level of sophistication in interacting with women, especially women who are above him in the social strata, is low. Any contact he has had with women he has found attractive would be described by these women as ‘awkward.’ ” The F.B.I. was right about the killer being a blue-collar male between twenty-five and thirty-five. But Lee turned out to be charming and outgoing, the sort to put on a cowboy hat and snakeskin boots and head for the bars. He was an extrovert with a number of girlfriends and a reputation as a ladies’ man. And he wasn’t white. He was black.
A profile isn’t a test, where you pass if you get most of the answers right. It’s a portrait, and all the details have to cohere in some way if the image is to be helpful. In the mid-nineties, the British Home Office analyzed a hundred and eighty-four crimes, to see how many times profiles led to the arrest of a criminal. The profile worked in five of those cases. That’s just 2.7 per cent, which makes sense if you consider the position of the detective on the receiving end of a profiler’s list of conjectures. Do you believe the stuttering part? Or do you believe the thirty-year-old part? Or do you throw up your hands in frustration?
Gladwell goes on to ridicule criminal profiling as a party trick, which takes advantage of the confirmation bias. Of course, if you’ve been following the research of people like Paul Meehl this won’t be too surprising. In experiment after experiment, the method of clinical prediction is routinely beaten by statistical prediction. (Gladwell himself gave an excellent example of this in Blink, when he discussed the diagnosis of heart attacks.)
I’d wager that, at some point in the near future, criminal profiling will move into a neuroscientific stage. There’s already been a lot of work done on the psychopathic brain, so that we finally have a basic understanding of what, exactly, turns people into such amoral monsters. At first glance, this pathology might seem hard to understand. On most psychological tests, psychopaths appear perfectly normal. Their working memory isn’t impaired, they use language normally, and they don’t have reduced attention spans. In fact, some studies have found that psychopaths have slightly above average IQ’s and reasoning abilities. They can solve puzzles and play chess better than most non-psychopaths. Their logic is impeccable. But this intact intelligence conceals a devastating disorder: psychopaths are dangerous because they are missing a crucial source of emotions.
For example, when normal people are shown staged videos of strangers being subjected to pain they automatically generate a visceral emotional reaction. Their hands start to sweat and their blood pressure surges. But psychopaths feel nothing. It’s as if they were watching a blank screen. Most people react differently to emotionally charged verbs like kill or rape than to neutral words like sit or walk, but not psychopaths. The words all seem equivalent. When normal people tell lies, they exhibit the classic symptoms of nervousness. Lie detectors work by measuring these signals. But psychopaths are able to consistently fool the machines. Dishonesty doesn’t make them anxious because nothing makes them anxious. They can lie with impunity.
When you peer inside the psychopathic brain, you can literally see this absence of emotion. After being exposed to fearful facial expressions, the emotional parts of the normal human brain show increased levels of activation. So do the cortical areas which are responsible for recognizing faces. As a result, a frightened face becomes a frightening sight; we naturally internalize the feelings of others. The brains of psychopaths, however, respond to these fearful faces with utter disinterest. Their emotional areas are unperturbed, and their facial recognition system is even less interested in fearful faces than in perfectly blank stares. Their brains are literally bored by expressions of terror.
This inability to generate negative emotions means that psychopaths never learn from their negative emotions. As a result, psychopaths are four times as likely as other prisoners to commit another crime after being released. For a psychopath, there is nothing inherently wrong with violence: it is just another way of getting what they want, a perfectly reasonable way to satisfy their desires. The absence of emotion makes the most basic moral concepts incomprehensible.
Hopefully, this research will one day lead to a more scientific brand of criminal profiling. If you’d like to learn more, check out The Psychopath: Emotion and the Brain.