Think of psychopathic traits as the dials on a studio mixing deck. If you turn all of them to max, you'll have a soundtrack that's no use to anyone. But if the soundtrack is graded, and some are up higher than others—such as fearlessness, focus, lack of empathy and mental toughness, for example—you may well have a surgeon who's a cut above the rest.
Of course, surgery is just one instance where psychopathic “talent” may prove advantageous. There are others. In 2009, for instance, I decided to perform my own research to determine whether, if psychopaths were really better at decoding vulnerability (as had been found in some studies), there could be applications. There had to be ways in which, rather than being a drain on society, this ability actually conferred some benefit. And there had to be ways to study it.
Enlightenment dawned when I met a friend at the airport. We all get a bit paranoid going through customs, I mused. Even when we're perfectly innocent. But imagine what it would feel like if we did have something to hide—and if an airport security officer were particularly good at picking up on that feeling?
To find out, I decided to conduct an experiment. Thirty undergraduate students took part: half of them high on the Self-Report Psychopathy Scale, and half of them low. There were also five “associates.” The students' job was easy. They had to sit in a classroom and observe the associates' movements as they entered through one door and exited through another, traversing, en route, a small, elevated stage. But there was a catch. They also had to note who was “guilty”: Which one of the five was concealing a scarlet handkerchief?
To raise the stakes and give the observers something to “go on,” the associate with the handkerchief was handed £100. If the jury decided that they were the guilty party—if, when the votes were counted, they came out on top—then they had to hand it back. If, on the other hand, they got away with it, and the finger of suspicion fell heavier on one of the others, they would, in contrast, stand to be rewarded. They would, instead, get to keep the £100.
Which of the students would make the better “customs officers”? Would the psychopaths' predatory instincts prove reliable? Or would their nose for vulnerability let them down?
More than 70 percent of those who scored high on the Self-Report Psychopathy Scale correctly picked out the handkerchief-smuggling associate, compared with just 30 percent of the low scorers. Zeroing in on weakness may well be part of a serial killer's tool kit. But it may also come in handy at the airport.
Joshua Greene, a psychologist at Harvard University, has observed how psychopaths unscramble moral dilemmas. As I described in my 2011 book, Split-Second Persuasion, he has stumbled on something interesting. Far from being uniform, empathy is schizophrenic. There are two distinct varieties: hot and cold.
Consider, for example, the following conundrum (Case 1), first proposed by the late philosopher Philippa Foot:
A railway trolley is hurtling down a track. In its path are five people who are trapped on the line and cannot escape. Fortunately, you can flip a switch that will divert the trolley down a fork in the track away from the five people—but at a price. There is another person trapped down that fork, and the trolley will kill him or her instead. Should you hit the switch?
Most of us experience little difficulty when deciding what to do in this situation. Although the prospect of flipping the switch isn't exactly a nice one, the utilitarian option—killing just the one person instead of five—represents the “least worst choice.” Right?