Synopsis: When we hear the term “psychopath,” we usually think of serial killers or other nasty villains. Rarely does anyone think of the mild-mannered neuroscientist next door. We talk to a psychologist and to a neuroscientist who happens to be psychopathic, about what the term actually means in the medical world, how it’s tested for in various people, the traits that most often set it apart from other conditions, and how many people who have psychopathic tendencies can function in a non-violent, productive way.

Host:Gary Price. Guests: Scott Lilienfeld, Professor of Psychology, Emory University, Atlanta, Georgia; James Fallon, neuroscientist at University of California-Irvine, author of “The Psychopath Inside: A neuroscientists personal journey into the dark side of the brain.”

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 The Psychopath Inside

Gary Price: When you hear the word “psychopath,” you undoubtedly think of the worst criminals of all time: Ted Bundy, John Gacy, Jeffrey Dahmer and other serial killers. But are they the only people who are psychopathic? And do we even know what a psychopath is? We talked to two researchers about the issue and learned some very surprising things about who these individuals are and how they manage in society. First, though, what is a psychopath? How do psychiatrists and psychologists diagnose them?

Scott Lilienfeld: In reality, there’s no real formal definition of what a psychopath is. Some of that is reflected in the current diagnostic system, which is now called the DSM-5. Oddly enough, psychopathy is not anywhere in the formal part of the manual. So psychopathy right now is more of a kind of research diagnosis.

Price: That’s Scott Lilienfeld, Professor of Psychology at Emory University in Atlanta, Georgia.

Lilienfeld: Most psychologists and psychiatrists think of psychopathy as a bit of a hybrid condition. So, psychopaths are, on the one hand, superficially charming and poised – and make a good first impression on others – but on the other hand, they are often callous. They tend to be guiltless. They tend to be dishonest, and they also tend to be self-centered and have poor impulse control. So that’s an odd mix of characteristics that often make psychopaths particularly dangerous interpersonally and, sometimes, even physically. Because they can lure us into thinking they’re normal or even better than normal. But, in fact, they have some very profound emotional deficits and also deficits in impulse control.

Price: If there is no hard and fast definition of a psychopath, how do you test for it? Lilienfeld says that right now there isn’t a formal diagnosis for psychopathy, and most mental health professionals look at it as a continuum that differs more in dimension rather than kind. However, there are some tests that can determine if a person possesses some of the traits.

Lilienfeld: There is a very well validated measure called the Psychopathy Checklist – Revised (PCL-R) developed by a Canadian psychologist Bob Hare, which is a very detailed, standardized interview where you ask the person about their personality traits, but you also rely pretty heavily on file information, chart information to corroborate – or in some cases – not corroborate what a person says, because we know psychopaths lie from time to time. Some of us, myself included, also use self-report measures like questionnaires to ask psychopaths about their traits that have been met with some skepticism understandably because, again, psychopaths tend to lie, and also don’t have a lot of insight into their disorder. But, by the same token, those kinds of measures also work fairly well in research settings, although I wouldn’t want to rely on them entirely in a clinical setting.

Price: One of the self-reporting tests is the Psychopathic Personality Inventory-Revised or PPI-R.

Lilienfeld: There are questions tapped, for example, the extent to which people are good at or enjoy influencing others, and the extent to which people are charming, the extent to which people enjoy taking physical risks; the extent to which people feel guilt or empathy towards others, the extent to which people enjoy manipulating others, and so on. At least on our measure, there’s no strict cut off, but the more people tend to endorse those kinds of items, the more suspicious you should become that they’re in the range of being a bit more psychopathic, but again, all of us score somewhere on that dementia – probably a continuum and lots of healthy people get moderate scores. In fact, probably at least a little bit of a dose of psychopathy makes us a bit interesting. Because a little bit of a dose of being charming, a little bit of a dose of being freewheeling and spontaneous isn’t such a bad thing. It’s probably only when a lot of those traits become very extreme that we have to start worrying.

Price: So, why do some people like Bundy and Gacy turn violent? What’s going on in their brains that aren’t going on in the brain of a freewheeling, risk-taking extreme sports star or slick salesman? Lilienfeld says that we don’t know the answer to that question yet, but it could have something to do with the anatomy of the brain.

Lilienfeld: Some people think maybe it’s just a matter of severity. Maybe the people who become violent, like Bundy, are just more severe than others – that’s one model. I don’t think the evidence supports that model, but I don’t think it’s a closed issue yet. I think it’s more likely the level of severity probably plays part of a role. There’s something else going on. So, there is some research from both personality work and also brain imaging work that some of the people who were a bit more successful, or better at staying out of trouble, seem to have somewhat better executive functioning – meaning ability to plan or organize, which is often manifested in the frontal lobe. So, parts of the frontal lobes of the brain. So, it could very well be the executive functioning, especially frontal lobe functioning may partly make the difference between people who are more or less successful, adaptive at least, superficially, and those who end up being more dangerous and more violent.

Price: One man who discovered he was a psychopath is James Fallon, a neuroscientist at the University of California-Irvine. He chronicles his discovery and the aftermath in his book, The Psychopath Inside: A Neuroscientist’s Personal Journey into the Dark Side of the Brain. He says he was looking at the genetics and PET scans from serial murderers and found that there were distinct patterns in their test results. A few months later, he was looking at the same kinds of tests – but for his own family. He wasn’t searching for psychopathy, but for Alzheimer’s.

James Fallon: So, we all went in to get PET scans done and genetics for this study. You know, I was analyzing both of the murders, and I had finished them when my family’s PET scans came in through, and they all looked normal until I got to the bottom one and it looked exactly like the worst murderers I had been looking at. I told the technician, “This is the wrong pile.” And they said, “No, no, no. This is your family.” They checked, and the machine came back, and I peeled back the code and it was me. “Haha, I get the joke.” The same thing happened when the genetics results came in. There was no indication of susceptibility of Alzheimer’s or anything else, but my genetics showed a very high sort of association with violence, aggression and low interpersonal empathy. Those two biological markers then set me on a quest.

Price: Fallon is not a violent serial killer – or violent in any way, whatsoever. In fact, he’s pretty normal: he has a wife and kids and holds down a challenging, but not a physically risk-taking job. So, if he was born with a brain and genes that have the same characteristics as a violent serial killer, is it the way he was brought up that made the difference? Is it nurture, rather than nature that creates a violent criminal out of someone with those brain patterns and genetic make-up?

Fallon: This is a particularly embarrassing part of this, the past two years. I was like, what they call, the poster boy in college for genes controlling everything – and I made a big deal of this – and then this happened, and all of a sudden, and I had to eat crow and say I was wrong. This really changed my scientific thinking. Not only did I discover things about myself and my family that were a little bit disturbing, but in some way, freeing – but it really showed how the impact of early environment has on what your brain does, and the behavior you carry out, and how it can overcome the natural disposition genetically.

Price: Fallon says that brain patterns and genes are only part of the story when it comes to determining who might become a violent predator.

Fallon: If they are abused and hit over the head – that kind of brain damage – it’ll show different damage, but it’ll show an underlying core set of abnormalities: low function in the orbital cortex, amygdala, the limbic or emotional cortex connecting them. It’s in all of them. You know, that pattern of low activity can be determined genetically by a certain combination of serotonin and dopamine alleles. Somebody who has that pattern can also be a bon vivant – a very impulsive bon vivant person, but not a criminal. So the brain pattern itself won’t tell you if somebody is a psychopath or a killer. This is not ready for the courtroom yet. Likewise, genetically, each complex behavior we have is kind of affected by 10 to 15 genes. Each one. So there’s not just one warrior gene; there’s like 15 of them, but nonetheless just having the genes themselves, it may really predispose you to being incredibly aggressive.

Price: What about treatment? If we can see what makes their brains and genes different from the rest of us, is there anything we can do to help a psychopath? Fallon says that the neuroscience of psychopathy has some important uses, but it can’t tell us yet how to cure someone.

Fallon: It’s being tested early in kids now. Can you change the behavior? But after that, especially from puberty on, it doesn’t look like you can cure psychopathy. There are some exotic ways, genetically, that you can probably do it, but that would involve surgery and all sorts of things that we may not want to do. But it will at least tell us which of our soldiers shouldn’t be going to war, which kids are vulnerable – because not everybody is vulnerable to bullying and abuse – so you know, a lot of kids are just resistant to it. But it’ll point to those that are, so if we know those kids early on, if a family knows that, and they can keep it secret, then they can make sure that kid is not subjected to the bullying and abuse that would really profoundly affect their later behaviors as teens and adults because it primes that and triggers it later. Now in terms of curing it, there’s still no cure.

Price: Lilienfeld says that intensive therapy might help some people – if the condition is caught early enough.

Lilienfeld: I do think there’s some evidence that behavioral therapy does reinforce adolescence for adaptive behaviors, and may be helpful for a subset of these kids, particularly if it is a very, very intensive treatment over a long period of time. What I don’t know is whether or not you can genuinely change their underlying personality traits. I’m not sure if you can change a guiltless kid into a guilt-prone kid. I’m not sure you can change a kid who is devoid of social emotion into someone who has these emotions, but you might be able to alter some of these individual patterns of behavior. Because after all, there are plenty of people who are not terribly emotional, but who learned how to channel that behavior into something a bit healthier, and just become kind of an independent type rather than people who are truly mean-spirited and hurt other people.

Price: Lilienfeld says that we might know people in our daily lives who exhibit psychopathic tendencies, but who are not dangerous, such as the co-worker you can’t trust. These people have learned how to control their own behavior to get along in society. However, if you do meet up with someone who has psychopathic traits, you need to set some very firm limits.

Lilienfeld: I think that one of the mistakes that one might be tempted to make is to let them get away with stuff. I think that with the students who might have some of these traits, one thing I’ve tried to do is just to be very structured, set very firm limits, be polite but also be firm because I think often times people who are psychopathic, is they see someone they like and they sort of see, “Oh, this is someone I can manipulate, someone I can get away with.” A lot of them are like sharks smelling blood and they’ll say, “Aha! This is someone who’s going to be a good person to prey on.” So, one has to be very consistent, very firm, very polite – but don’t get angry. You have to make sure you don’t let psychopaths get to you either. That kind of approach can be also be very helpful with people who have psychopathic traits.

Price: You can read how a man with a psychopathic brain and genetic make-up manages to live and thrive in society in James Fallon’s book, The Psychopath Inside, available in stores and online. For information about Scott Lilienfeld and his work at Emory University, visit their website at For information about all of our guests, log onto our site at You can find archives of past programs there as well as on i-Tunes and Stitcher. I’m Gary Price.