Book Report: The Psychopath Code

The Psychopath Code: Cracking the Predators that Stalk Us. Author: Pieter Hintjens. Available as a paperback from Amazon or as a free e-book.

In paperback, it's 285 pages and very easy to read.

Thanks to Sarah for the recommendation.


What is a psychopath?

A "psychopath" or a "sociopath" is not a serial killer, at least in most cases. Instead, he (or she!) is simply a social predator or parasite. Someone whose life strategy is to prey on others, both individuals and groups. Someone who seeks to form exploitative relationships rather than mutually-beneficial relationships. An antisocial rather than a prosocial person.

Crucial here is the notion that psychopathy is an adaptation to the game-theoretic conditions of human social life. Being a psychopath isn't a disease state; it's a valid biological strategy for a human organism. That said, it's not necessarily better (more effective) or worse (less effective) than the "normal" prosocial life strategy. It's just that these strategies exist in rough equilibrium, like predators and prey in any ecosystem. More here.

While warning that there's no foolproof way to identify a psychopath (because they're experts at hiding), the book nevertheless paints a profile that can be used to help identify one. More broadly, however, the book is about how psychopaths operate, using the predator/parasite model as an overarching framework.

Major insights (for me)

  • Psychopaths are all around us, trying their best to hide in plain sight. Hintjens estimates that 4 percent of people are psychopaths (which may be high; see below). This helps explain how some people can act as scammers, con artists, and pathological liars, and yet still "live with themselves." They simply aren't like normal people; they're qualitatively different: professional manipulators with a different mental/emotional architecture.
  • A lot of the things we do in "normal" social life might be adaptations that defend against psychopathy.(*) For example: extended courtship periods, arranged marriages (see below), owning a pet, even board games. Psychopaths, apparently, aren't interested in simply spending casual, low-key time together with friends; it's too boring, not enough opportunity for them to exploit. So when prosocial humans pass casual time together, we feel closer to each other, more (subconsciously) assured of each other's good intentions. For more, see Sarah Perry's "Dares, Costly Signals, and Psychopaths."
  • (*) I've long understood that much of human social life (e.g., costly rituals) can be ways to mitigate cheating and freeloading. But I always modeled cheating and freeloading as behaviors that flow, opportunistically, from people who are otherwise normal and prosocial. This book really helped me to see that, in addition to casual/opportunistic cheaters, there are also professional cheaters who specialize in exploiting others. It's a slightly different threat model.
  • Port-scanning. This is my term (not the author's) for a behavior I've noticed in a handful of my acquaintances. Instead of getting to know someone slowly, relishing in his or her personality and opinions about neutral third-party topics, a "port scanner" asks rapid-fire personal questions intended to suss out important information about the target, e.g., assets and weaknesses. On the receiving end of a port scan, I've often felt uncomfortable. But until reading this book, I had no idea why. I'm certainly not accusing everyone who uses "port scanning" of being a psychopath, but it seems like good Bayesian evidence of it.
  • Supernormal stimuli. This was one of the most interesting passages of the book. I've read about these before, but I don't think I ever realized that they could be as abstract as the ones described in the book. According to Wikipedia, a supernormal stimulus is "an exaggerated version of a stimulus to which there is an existing response tendency, or any stimulus that elicits a response more strongly than the stimulus for which it evolved." Classic examples include candy bars and pornography. But Hintjens describes some more exotic supernormal stimuli, e.g., an older male engaged in an act of public speaking, with confident body language, describing plans and making promises of huge windfalls. One way to understand this, Hintjens says, is as a supernormal stimulus preying on our evolved instincts for identifying and following leaders. A lot of cults, including startups, seem to make use of this supernormal stimulus. And clearly these tactics are ripe for abuse by psychopaths.


  • I suspect that Hintjens overestimates the proportion of psychopaths in the general population ("4 percent"). He's almost certainly right to suggest that there are more psychopaths than people who would fit the classic diagnosis of "antisocial personality disorder," and he's also right to look beyond those who are physically violent. But he also counts as a "psychopath" everyone who would receive a diagnosis of narcissistic, borderline, or histrionic personality disorder. In my experience, someone can be a narcissist without being a psychopath. I've also polled a few of my friends (an admittedly biased sample) about their interactions with psychopaths, and from their experiences, 4 percent seems grossly high. Personally, I can only identify 5 plausible psychopaths from my network (of which I expect only ~3 are actually psychopaths), out of maybe 200 to 300 people I've had enough interactions with to venture a guess about. But of course there may be many I simply can't detect.
  • Hintjens tells us that psychopaths only feel the "predator emotions": hunger, obsession, euphoria, glee, fury, bloodlust, gluttony, satiation, frustration ("blocked"). This is an intriguing possibility, and I could certainly believe that psychopaths have a radically different emotional life, including an absence of many "universal" human emotions like guilt and shame. That said, I find it hard to believe that psychopaths would not feel the defense emotions (e.g., suspense, anger, shock) or the sexual emotions (e.g., interest, lust), or even some of the tribal emotions (e.g., outrage, submission).
  • The book itself is breezy, anecdotal, and makes a lot of flippant claims. Overall, I find the author somewhat unreliable, although I think he's absolutely onto something with his main themes and I think he has good intuition about what psychopaths are and how they behave. I took just about everything with a grain of salt.

Highlighted passages

On arranged marriage as a defense against psychopaths (ch. 2, p. 73):

When a family is wealthy, in a country with a weak state, it presents a lucrative target. Strong families in developing countries develop a culture of arranged marriages. They vet candidates with paranoia. One bad choice can destroy generations of accumulated family wealth.

This model lets us make a prediction about any given society: the rate of arranged marriages will correlate with social status of the pair. The higher their status, the less free choice in marriage. This seems true in all societies. Between societies, the weaker the state, the higher will be the rate of arranged marriages. This is because weak states cannot protect a family's wealth from predators.

On the binary nature of psychopathy (ch. 4, p. 137):

I don't think you can be a little bit psychopathic. Whether you play the social game, or the cheater game, you must play to win. Mallory is competing with other psychopaths, and Bob with other Bobs. ["Mallory" is the author's name for a generic psychopath, while "Alice" and "Bob" are normal prosocial humans.]

I'm willing to believe it's mostly binary, but could be persuaded otherwise.

On the "dance of emotions" (ch. 6, p. 192):

To learn the dance of the emotions is like learning to read. Emotions are a language. It is an ancient language that we share with many other species. The language flows through us, and between us. We speak it with our bodies and faces. We feel it in our blood as music. We move to the music without conscious decision. We must answer the call of emotion, even when it hurts and damages us to do so.

Great description of why we have emotions (ch. 6, p. 194):

Emotions have two general goals. First, they prepare our mind and body for some action. They speed up certain systems and slow down others. I call this "orchestration." Imagine the emotion as the conductor waving a baton to get a hundred musicians to play the same tune.

Second, emotions display our mental and physical state to others. They do this using facial and body language. The language of an emotion is often based in real physiological activity. It may also be synthetic. Emotional languages are universal across humanity.

Some emotions are only about orchestration. Others are only about display. Most are a mix of the two.

On shame and the inability(?) to fake a blush (ch. 6, p. 217):

Shame — the emotion which says, "I'm aware that I broke the rules." Again, this is about detecting professional rule breakers. Shame has a specific skin flushing pattern: face and ears. Mallory can mimic the body language, yet he cannot blush nor show red ears. Shame is such a powerful psychopath filter that social humans also mimic it, by blushing.

An asymmetry between predator and prey (ch. 7, p. 243):

The predator lifestyle is risky. A predator cannot afford even minor injuries. Non-human predators attack the weak, the immature, the old. Never an adult, capable of fighting back. A cow with a broken leg can still eat grass. A lion with a broken leg will starve. This defines the level of violence a predator will exercise. It will choose the easier prey. It will not fight another predator except to survive or reproduce. It will use bluff and noise to intimidate, yet will flee from a real fight.

On how to beat a psychopathic liar (ch. 7, p. 247):

Sooner or later, careful documentation always beats charismatic story telling.


Last updated May 30, 2016.