Actually, I now realised, I had been a somewhat power-crazed madness-spotter for twenty years. It is what we journalists do. It was why I had taken to being a psychopath-spotter with such aplomb. I was good at spotting the diamonds of craziness amid the gloom of normality because it’s what I’ve done for a living for twenty years….This is why I love Jon Ronson so much, since his early Human Zoo column, to his more recent Adventures with Extremists and The Men Who Stare at Goats. Here he explores the world of psychopathy, uncovering its nebulousness and inherent struggle with being a label – albeit one with a 20 part checklist.

The Hare PCL-R checklist, or ‘psychopath test’ is made up of 20 personality traits typical of psychopaths (such as grandiose sense of self worth, a lack of remorse or guilt, shallow affect and poor behavioural controls). Suspects are scored with a 0, 1, or 2 for each trait, and then their score is tallied up. With 40 the top score, you are deemed ‘psychopath’ if your score hits mid-20s. Ronson litters his colourful journey amongst suspected psychopaths (including a CEO of a billion dollar company, a Broadmoor inmate, and a conspiracy theorist with a Messiah complex) with his own trademark neurosis and regular self-assessment on the Hare scale.

It’s thought provoking all along the way – what makes up madness? how useful are labels? how crucial is empathy and our amygdala (the complex part of the limbic brain that is crucial to our ability to empathise). Hare believes psychopathy all comes down to a non-functioning amygdala, which means no chance of rehab. Ronson isn’t so sure it seems.