People with persistent predatory personalities cause an inordinate amount of pain - a fact that will surprise absolutely no one who has ever met one. But recently, our shared understanding of them has grown, and it could help protect us. Hooray for progress.

The classic checklist for psychopathy was developed in 1980 by Prof Robert Hare, who remains the undisputed heavyweight champion of the field. The 20 traits, ranging from pathological lying to a lack of empathy, were based entirely on prison populations. This was a smart move: Hare had a large sample with pronounced psychopathic behaviors, and he could cross-reference interviews and self-reports with official data on the individuals - so any inconsistencies were promptly exposed. It’s almost like psychopaths aren’t great at telling the truth.

But Hare knew this approach had its limits. As far back as 1976, he admitted he had no idea how much his findings applied to non-incarcerated psychopaths - including, you know, women. “Research into the socially successful psychopath is badly needed,” he concluded, presumably while eyeing a politician warily. Even decades later in the early 2000s, when Hare wanted to study psychopaths in politics, he still had to go to prison to find them (specifically, Pinochet’s henchmen in Chilean jails). Because apparently, the higher-functioning psychopath - the one who doesn’t get caught, or maybe doesn’t even resort to crime - is as elusive as a unicorn that lies.

And here’s the kicker: self-reporting questionnaires don’t work on these people. Psychopaths lie; arguably, that’s their defining trait. So how do we spot them? The article suggests it’s like telling apart a domestic cat from a wild cat - subtle but crucial. One will scratch your sofa; the other will eat your face. Both are charming in their own way, but one is decidedly more dangerous.