Human Lie Detector: The #1 Sign They’re Lying To You, Catch Liars Instantly! | Dr Leanne ten Brinke

How long does it take someone to spot a psychopath?

About 5 seconds.

Most people think a psychopath looks dangerous—they picture the villain in a movie, but that's not how it works in real life. We've done some research in my lab, and we found there are certainly some things that you can look for.

Have they ever done that with lying, to figure out if people can spot liars?

Thousands of times. If you ask people what the number one cue is that someone is lying to you, they will say they can't look you in the eye. But there's no research to suggest that that is true. However, there's an essential tool for detecting lies, which is—

Oh—

—I know, as I study dark personality.

As I study dark personality traits, I've found there are four different elements: psychopathy, Machiavellianism, narcissism, and sadism. What we found is that people with higher levels of these traits engaged in Duchenne smiles—which is the activation around the eyes—and they also used a lot of hand gestures.

Where does this come from? Research suggests that abuse, a cold and uncaring parenting style, but also overvaluation of a child early in life may lead to more narcissistic views later.

Have you pursued any other fascinating questions in your lab? Yes—we studied the extent to which psychopathic personality traits could increase the amount of influence you have in government. There are also three common mistakes people make when dealing with dark personalities, which we'll get into more later. And I'm wondering if you can spot any of these dark personality traits just by looking at dating profiles.

All right, so this is Ryan. This feels like a red flag. Then there's Haley—that would be associated with psychopathy. Okay, David is a brain surgeon. Very impressive, but I'm seeing narcissism.

So this begs the question: if someone has those traits you've described, can they be cured? So, in my lab, what we found is that...

This is super interesting to me. My team gave me this report showing how many of you who watch the show subscribe, and according to it, some of you have told us you're randomly unsubscribed from the channel. So a favor to ask: please check right now if you've hit the subscribe button. If you're a regular viewer and you like what we do here, we're approaching quite a significant subscriber landmark. If there was one simple, free thing you could do to help us keep this show free and improving year over year and week over week, it's just to hit that subscribe button and double-check you've hit it. That's the only thing I'll ever ask. Do we have a deal? If you do it, I'll make sure every single week and month we fight harder and harder to bring you the guests and conversations you want to hear. I've stayed true to that promise since the very beginning of the Diary of a CEO, and I will not let you down. Please help us—really appreciate it. Let's get on with the show.

Professor Leanne Tenbrink, at the very heart of your motivations, why is it you do what you do?

I want to make people less cynical about human nature, which might seem paradoxical given what I study, because I study deception, dominance, and so-called dark personality traits. But when you understand those topics—and also that there's something you can do about them to make these interactions better—it's incredibly powerful and can give us a more accurate view of the world.

Why is the general public so fascinated by these subjects? What lies beneath that curiosity—what are people trying to figure out when they take an interest in psychopathy?

I think one reason we're so drawn to psychopathy is that it's quite foreign to us. Most of us move through life caring about other people, feeling compassion, telling a few lies here and there but by and large being truthful and playing by the rules. That's essentially the opposite of psychopathy. When you're confronted with a personality so contrary to your whole experience of being alive, your reaction is: what's going on here? I want to understand that.

There's also another element—there's actually some research on true crime specifically and why people are drawn to it. The audience tends to be largely female, and among the motivations people report are wanting to understand these offenders and wanting to avoid becoming a victim of such people.

"Is it possible to spot someone who is a psychopath?"

"Yes."

"How long, according to the research, does it take someone to spot a psychopath?"

"You can get a kernel of truth about someone's personality—the extent to which they're psychopathic—in about 5 seconds."

"Explain the research to me."

"This is research by Scott Lilienfeld and his colleagues. They showed people 5-second, 10-second, and 20-second clips of interviews in which criminal offenders were being interviewed by a psychologist and rated on their psychopathic personality traits. Random psychology student volunteers watched 5 seconds of that interaction and made ratings—how callous do they seem, how manipulative do they seem? They found a pretty reasonable correlation between the ratings of these naive viewers watching 5 seconds and the trained clinical psychologists who conducted hours-long interviews and gathered collateral information.

We partnered with Scott, got these videos, and coded the verbal and non-verbal behavior—are these people behaving differently, and what are people paying attention to?"

In our study with Scott, we coded verbal and non-verbal behavior from the interviews and found that people with higher levels of these psychopathic traits engaged in what we call Duchenne smiles — a genuine-looking smile.

What distinguishes the two kinds of smiles is activation around the eyes, which creates crow's feet — lines in the corners of the eyes.

So a genuine person will have crow's feet when they smile?

Theoretically, yes. Botox and other things can obviously get in the way of this, but it's totally in the eyes. With a non-Duchenne smile, you get the same upturned lips, maybe showing teeth in a big grin, but no activation around the eyes, so no crow's feet.

People high in these psychopathic personality traits were showing very happy-looking smiles while saying really hostile things — happy expressions and hostile language at the same time, producing a strange emotional presentation. They also used a lot of hand gestures, which we called illustrators. Random observers noticed those gestures and used them to guide their judgments. That's very little information to go on, but it suggests you can get a sense of someone relatively quickly. Still, personality exists across time and context, so you get better data the more data you have across different times and places.

Faked Sadness in Missing-Person Appeals

This is sadness. Some of my research looked at people who went on TV asking for help finding their missing loved one — and in some proportion of those cases, they had actually killed that person. They were falsely pleading for help for someone they knew was never coming back.

Wasn't this your PhD?

Yes. It was in psychology, but in a forensic context at the time — I was studying behavioral cues to high-stakes emotional deception, comparing cases where the person was guilty against cases where people genuinely had no idea where their missing loved one was and were desperately pleading to have them home.

This was one of the differences we saw in those videos. Try this with me: in genuine sadness, the lip corners turn down — you did that pretty easily. What tends to be more difficult is the eyebrow combination: the inner eyebrows come upward and together.

What we saw in the people who were lying was more like surprise. They could pull the lip corners down, but instead of the inner eyebrows going upward and together, the whole inner and outer eyebrows would go up, but not together.

Could you predictably tell from footage whether someone had done it? Yes. We used four different cues—two verbal and two non-verbal—to predict with about 90% accuracy who was lying and who was telling the truth.

One caveat: when we tried to replicate that more recently, we found much more modest effects. But there were consistencies, especially with the verbal cues. There, it came down to the number of words people used as well as tentative words. Liars would say things like "if you see this, come home or call or whatever," leaving it vague about what the person should actually do, or "it wasn't like an argument per se that we were having"—they left a lot of gray area in what they said. Truthful people, by contrast, would say "when you see this, call me."

So they were more high-conviction and precise?

Yes, exactly.

One cue to deception is sparse or ambiguous information. The most consistent effect we have for differentiating truth tellers from liars is the amount of detail they give: people who are lying tend to give fewer details.

"Interesting — I thought it was the opposite."

I hear that a lot — people say liars will natter on and on. That's not what we find in the research whatsoever, especially when people haven't had time to prepare. With time to prepare, someone can look pretty much like a truth teller in how much information they offer. But if you put someone on the spot, the truth teller just has to remember what happened and tell you — and you can even ask for more, like "tell me more about that," because they were there. The liar has a much harder task: we call this increased cognitive load. They have to invent details on the spot, avoid contradicting themselves, remember the lie for next time, and figure out what you already know so they don't step in it while explaining what didn't actually happen.

"They must have higher blood pressure anyway just from knowing they're not telling the truth — that must spike your cortisol."

We've actually done research in my lab showing that people who are lying tend to have increased cortisol reactivity relative to truth tellers.

The reason I was surprised is that I'm a big true crime fan and watch interrogation videos, and I thought I'd heard that guilty people give lots of irrelevant detail. I was watching the Jesse Smallet TV interview — he had time to prepare, so maybe that's the caveat — and he described a bunch of pointless stuff: how he landed, called his manager who was in Australia because his manager was on tour with someone else. Even when he talked about going to Subway, he specified it was a tuna wrap. The details he was sure of and that were probably true, he really expanded on — but where the bulk of the alleged lies took place, it was quite vague.

We call that embedded lies: lots of detail where it's truthful, almost no detail where it's a lie, then lots of detail again where it's truthful. You can also compare against someone's baseline — do they normally give lots of detail or are they usually sparse? — and look for deviations. If someone tells you a long story full of detail and then one part is very sparse or ambiguous, that can be a red flag.

What's important to remember is that there is no Pinocchio's nose — no single cue. What you're looking for are subtle cues that act as red flags and encourage you to follow up, ask more questions, and dig into that topic a little further.

Researchers have run similar tests to see whether ordinary people can tell, just on the surface, if someone is a psychopath within 5, 10, or 20 seconds. Has the same ever been done with lying — can people spot lies?

Literally thousands of times. In my lab, we've had participants steal a $100 bill from a room, then brought someone in to essentially interrogate them, and everyone had to deny it. The people who took the bill were lying; the people who didn't were telling the truth — with $100 on the line. If you could convince the interrogator you didn't take it when you actually did, you got to keep the Benjamin. Then we showed these videos to other people. People are not very good at detecting these lies, or really any kind of lies. On average, people perform at about 54% accuracy — if I gave you 12 videos, six liars and six truth tellers, you'd get about six or seven right.

What if someone is trained? Do the numbers improve?

They can improve a little. What works better, though, is learning how to ask better questions. Instead of just watching a video and judging whether someone is lying, good lie detectors ask for more information, or they ask unanticipated questions the person hasn't prepared for. Then the cues of deception — the sparse information, the sense that they're thinking really hard — really go off the charts. Learning to ask good questions is an essential tool for detecting lies.

I have to be careful here, because people will take this out of context: say I suspect my partner is cheating. I sit them down and say, "Babe, are you cheating on me?" and they say, "No, absolutely not." What would be a good question to find out if they're actually cheating?

Your first mistake was asking a closed-ended question — "Are you cheating on me?" You didn't even give them an opportunity to have to come up with something more difficult. Instead, you'd say, "Okay, I think last Friday night you said you had to work late, but I don't really believe that. I think you were out with someone else. Tell me about work on Friday night." That's an open-ended question.

Role-play: catching the lie

Let's role-play. You suspect I'm cheating, and last Friday night I was up to something — that's the context.

Okay. I know you had to work late on Friday night. What were you working on?

Yeah, a big investment deal we're working on with a couple of colleagues. We had to get a deck together, so I stayed until 3:00 a.m. or something crazy like that, and I ended up falling asleep at my desk. Anyway, what are we doing today? What's for dinner?

Okay, red flags flying up. So I'd ask more questions: "What client were you working on this for? What's the deck about?"

It's an investment deal with Google. Yeah, it's Google.

I could ask you to tell me what was in the deck, and you'd give me somewhat sketchy information. A great question to have in your back pocket is simply: "Tell me more about that." You don't even have to try hard to figure out where you're going to stump them.

At some point, the liar is going to have much more trouble coming up with additional details than the truth teller. The truth teller was actually there and knows all those annoying little things — like not being able to get the font on the slide deck to stay put — that maybe didn't make it into the first version of the story, but that they can expand on when asked for more detail. For the person who's lying and making it up, that's much more difficult, because it didn't actually happen.

Liars will also be somewhat vague, and the details they do give are hard to verify — for example, "the new guy at work," someone you can't check with. In general, liars tend to give fewer verifiable details.

There's a fascinating study on this. When we try to dissect someone's behavior, we pay attention to their words, whether they're fidgeting — which is actually not a good cue to deception — or their eye contact, also not a good cue. We try to build this crazy algorithm in our head, adding up all these behaviors to decide whether someone is lying. But research suggests that simply asking how verifiable was that statement is a better strategy for accurately detecting lies than using all those other cues that don't work.

How verifiable is the excuse this person gave me?

The broader finding is that it's better to focus on one cue that works than to combine lots of little cues that mostly don't work at all.

The third sign is visible cognitive effort. Making up details is hard, so a liar might speak really slowly, use lots of ums and ahs, or furrow their brow while trying to figure things out. It's important to remember that you could pause for a million reasons unrelated to deception — you might just be trying to remember something, or furrow your brow because your forehead itches. So none of these are Pinocchio's nose, but they are reliably associated with deception.

What about body language? People put a lot of stock into it, particularly gaze aversion. If you go around the world and ask people what the number one cue is that someone is lying, they will say sketchy eye contact — and there's no research to suggest that's true.

It makes sense when you think about it for a moment: we all know the stereotype that liars can't look you in the eye, so if I want you to believe me, I'm going to make sure I control my eye contact. And eye contact is well under our control.

There are also neurodivergences that mean some people struggle with eye contact, which doesn't necessarily mean they're lying. In fact, emerging research suggests that people on the autism spectrum are perceived as lying more when they're actually telling the truth — because of this eye contact cue, which people treat as a sign of deception but which is in fact unrelated to it.

There are cultural differences too: in some cultures it's more respectful not to look someone in the eye, which can also lead to errors in judgment.

The interviewer raised the "dark triad" of personality traits, and the guest corrected it: it was a triad, but is now a tetrad — four traits. He then explained each one.

Psychopathy

Psychopathy is a constellation — a set of personality traits, not just one thing. People high in it have superficial charm, are quite manipulative, and tend to be grandiose, with an inflated view of themselves. There are emotional components too: shallow emotional experiences, a lack of remorse or guilt for harming others, and a tendency not to take responsibility for their own actions.

They also tend to be impulsive, living by the seat of their pants without planning far into the future — for instance, mooching off family members or romantic partners. Finally, they break a lot of rules, from workplace rules and social norms up to laws, since psychopathy has largely been studied in criminal populations.

Machiavellianism

The other three traits of the dark tetrad share some elements with psychopathy but have unique flavors. Machiavellianism is named after Niccolò Machiavelli, who wrote The Prince, a kind of how-to manual for gaining and wielding power effectively.

As a personality trait, it involves cynicism about other people and a lot of lying and manipulation — but more like three-dimensional chess. Someone might learn a small tidbit about you and think, "I could use that against him later; I'll put that in my back pocket," keeping it available for future manipulation or blackmail. They are very interested in power, which is where the name comes from.

Narcissism

Narcissism is the trait people know best: these individuals tend to be very entitled and willing to exploit others to get what they think they deserve — a relentless kind of self-focus.

The interviewer noted that the word gets thrown around constantly in culture, and asked for his view. He replied that narcissism, like all these traits, exists on a continuum. Anyone can take a self-report measure and land anywhere from very low to very high. At the incredibly high end, narcissism has a personality disorder diagnosis in the Diagnostic and Statistical Manual — essentially a list of mental disorders — so a psychologist or psychiatrist could assess and diagnose someone with extreme levels.

Part of the problem, he argued, is that people make a binary distinction: "She's a narcissist," "He's a psychopath." He has qualms with that usage for a couple of reasons: these traits exist on a continuum, with no clear moment where someone becomes "a narcissist" versus not. It's a bit of a mouthful, but it's more accurate to say someone has relatively high levels of narcissism or psychopathy.

Grandiose vs. vulnerable narcissism

The interviewer noted the guest had said there are two main types of narcissist. Increasingly, personality psychologists identify a vulnerable type and a grandiose type. The grandiose type is the one everyone knows: a huge ego that cannot be popped — negative feedback doesn't get through, and they always think they should be in charge. These individuals tend to get very angry at a particular kind of threat to their ego: failure to achieve, such as wanting a promotion at work and not getting it.

Vulnerable individuals, by contrast, have a very fragile ego.

So the ego can be popped very easily, essentially. If they get negative feedback from people—maybe they get socially rejected—that's when they become quite angry. That's more of a trigger for them. And yes, "angry" is the outcome for both types of narcissists, though one might assume from the wording that a vulnerable narcissist would get more upset or more self-critical. The research at least focused on anger in response to these kinds of threats to their ego, but certainly it's emotional, combative—this is when you're going to get a really negative response. Someone who is relatively low on narcissism of both kinds could take that kind of feedback—like, "No, I don't think a second date is really for us"—whereas someone with vulnerable narcissism is going to respond badly.

The interviewer explains why he asked: he was interviewing a candidate who was very quick to claim credit for everything the company they'd worked at had done, and very quick to say they were good at everything. Even as he walked out of the room and asked, "Can I message you on this particular app?" they said, "I'm amazing at that app." (He's anonymizing, so details are slightly changed.) Having interviewed thousands of people over the years, he walked out thinking they were so lovely, but it felt like it was coming from a place of insecurity. Their story was one of someone continually counted out, overlooked for opportunities, with a bit of a chip on their shoulder, trying to prove themselves. Another person might look at that same pattern and say, "That person's a narcissist." So he wondered whether vulnerable narcissism was linked to this: that they respond so poorly to rejection because they need constant admiration and positive feedback from other people to keep their ego going. He called the candidate's former employer for a reference, and one of the quotes was: "He always needs a gold star."

What's the difference between deep insecurity and narcissism in this regard? Deep insecurity would need to be coupled with entitlement—there's still a grandiose sense of self, just a quite fragile one. They think they're really good, they're willing to exploit other people to get what they think they deserve, and they may feel victimized—that's why they haven't gotten the accolades they think they deserve. Regardless of where this person sits on that continuum, they might still have incredible skills and the abilities you're looking for. So the question is whether it's something you can manage or whether it's going to create problems.

The interviewer says he got no sense that the candidate was entitled or would use other people to their advantage—people would generally like them, and they weren't entitled at all, but they still had self-promotional traits. In society, the minute someone is overly self-promotional, we run to the narcissist category, when it could be other things.

Yes—in that situation you need to be mindful of the situation itself. Behavior is a combination of both our personality and the situation we're in. At a job interview, your whole goal is to show people you can do the job and have the skills they need, so in an interview we might come across as more confident, presenting ourselves in the best possible light. But we're very quick to rush to a personality assessment—this is called the fundamental attribution error. When I see someone behave a particular way, maybe being self-promoting and saying all the things they can do really well, I could think, "Oh, that's narcissistic"—as if it were a personality trait.

We tend to make these personality attributions about others more readily than about ourselves. If I were in their shoes, I would say I was just trying to show Stephen what I could do — the situation made me act kind of bigger than my britches. So we need to be aware that situations can shape behavior, and avoid being too quick to make a personality attribution when the situation could explain it.

An important point here: personality is a consistent pattern of thinking, feeling, and behaving over time and across contexts. If you've only had one interaction with someone, you might get a sense of their personality, but you might also see them out with friends or family where they aren't so boastful — which suggests the situation was talking, not the personality.

Are there gender differences in narcissism, across vulnerable and grandiose types, or in our ability to spot these behaviors?

For all of these traits, men tend to score somewhat higher than women, and that's a quite consistent finding. That doesn't mean women can't score very high — there are certainly cases and quite a bit of overlap — but on average, men's averages tend to be higher than women's.

The fourth and newest trait is sadism. Hearing the word, you might jump to something extreme — and it can be. I first started studying sadistic behavior in the context of sexual homicides, reading descriptions of criminal behavior and looking for signs of sadistic treatment of victims. It can get incredibly extreme, and that's probably where our minds go. But there are also more everyday versions. A good example is online trolling: people relatively high in sadism take pleasure in other people's pain, and you can express that in gruesome, horrifying ways — or just by pushing people's buttons online to get them upset.

What these traits all share is three things: they are callous, not caring about other people's feelings or outcomes; manipulative, willing to lie and cheat to get what they want; and hostile toward others. That's the core of all of them.

Are they good at hiding it?

Yes. Some of the earliest descriptions of psychopathy in particular described it as a "mask of sanity." They can seem quite normal on the surface, but if you get a look underneath the hood, you see they're not running the same operating system you are.

The interviewer asked about the inverse of these traits: beyond what people understand, there are also misconceptions — for example, the common claim that narcissists or psychopaths can't hold eye contact. What has the research debunked?

One of the biggest myths is that all people with high levels of psychopathy are violent, and that's absolutely not the case. Most people think a psychopath looks dangerous — they picture the villain in a movie — but that's not how it works in real life. In the four-part description of psychopathy, there is indeed a rulebreaking element, and sometimes that's criminal rulebreaking, which could be violent behavior, but it's not necessarily so. Psychopathy is a risk factor for violent behavior, but plenty of people score relatively highly and never engage in violence. They might break rules in other ways.

Whenever we hear the word "psychopathy," what comes to mind is a Ted Bundy type character. He reportedly scored around 39 out of 40 on the Psychopathy Checklist Revised, the measure psychologists use to assess how psychopathic someone is. He's a bit of a poster boy for those traits, but people can certainly score highly without being a serial murderer.

The interviewer asked how common these dark personality traits are in the population. The guest explained that it's a complicated question, because all these traits exist on a continuum — the proportion of people counted as "high" depends entirely on where you set the cut point.

For psychopathy at clinical levels — a score of 30 out of 40 or higher on the Psychopathy Checklist-Revised — that's about 1% of the population. Narcissistic personality disorder, meaning extreme levels severe enough to warrant a diagnosis, would be 2 to 5 percent.

There are no clinical cut-offs for sadism and Machiavellianism. What exists instead is a large amount of data from self-report questionnaires. One way to gauge how many people are high on these traits is to look at the proportion who on average agree with the items — for example, "I am a born leader" is a narcissism item, while liking to see other people get hurt is a sadism item. Counting the people who on average agree with these items, it's about 10% of the population.

Where does this come from? When you look at the individuals in these photos, does their antisocial or dark triad behavior stem from childhood trauma, genetics, or something else?

The answer is both. Research suggests that for psychopathy and narcissism, quite similarly, the variation in someone's score on that personality trait is about 50% genetic and about 50% environmental experiences. In some ways, this makes us realize these people didn't ask to be this way: you don't get to choose your parents, so you don't get to choose your genetics. And when it comes to environmental experiences, they're often early life experiences, and not good ones. Research suggests that abuse and a really cold, uncaring parenting style early in life can increase the likelihood that someone will have higher levels of these traits later in life.

For narcissism, another variable is overvaluation of a child early in life. In one longitudinal study, researchers asked parents the extent to which they told their kids things like "you're special, you're better than other kids." The more kids got that kind of feedback, the more likely they were to be narcissistic later down the road—they thought they were exceptional, entitled to things other people were not entitled to. That's different from self-esteem. We want our kids to have high self-esteem; we want them to know they are cared for and worthy. That comes from something different: a warm, responsive parenting style.

I was thinking about causation, though. If the parents themselves had a genetic disposition to be narcissistic, is it conceivable that they spoke highly to their children—and maybe it wasn't the nurturing, it was their nature? That child would also share the genetics of the parent who had the proclivity to tell them they were the most amazing thing ever.

Totally. I mostly think about this in the context of psychopathy, where sometimes you get a perfect storm. You might have a parent with really high levels of these traits, passing on that genetic risk factor. But if a parent in your household is callous, manipulative, and impulsive, it's going to be very difficult to maintain a stable home life for that child. So they might end up experiencing the abuse and cold parenting styles that are also environmental risk factors for developing psychopathy later in life. They get a double whammy.

Asked what the research on dark personality traits and self-esteem suggests about being a good parent, the answer is that warm and responsive parenting is the approach that works. When you look at treatment for kids showing early warning signs of callous and unemotional traits, that's the treatment that seems to work.

The silver lining in this dark research area is that early intervention really can help reduce the likelihood of children developing high levels of psychopathic traits as they grow older. And it's usually training for parents, not a child seeing a therapist once a week. Parents learn how to respond in ways that don't escalate into dominance contests when the kid acts out, and how to reinforce and model warmth and responsiveness.

What's fascinating about psychopathy and callous-unemotional traits in kids is that they tend to be not very responsive to punishment, but very responsive to rewards. Parent-child interaction training teaches parents to notice when a child does something kind or helpful, repeat what the child said — "that was a very kind thing to say" — pay attention to the behavior, reinforce it, and give that attention to increase the likelihood of seeing it again in the future.

The inverse — the bad way to respond that may lead to these dark personality traits — is cold and unresponsive parenting: getting angry and frustrated with the child. Physically harming them is child abuse, and it's associated with an increased likelihood of developing these traits over time.

On dominance, this isn't exclusive to parenting kids with callous-unemotional traits, but consider a tantrum: a parent says "No, you can't have that," the child escalates, the parent repeats "No, you can't have that," and then once it reaches a certain point, the parent gives in. What that teaches the child is that escalating behavior works — keep dominating, kick it up a notch, and at some point you'll win. That kind of parenting won't extinguish negative behavior very effectively.

The brain scan on display is a functional MRI, with the prefrontal cortex highlighted. Research suggests that people with high levels of psychopathy tend to have a less active and less connected prefrontal cortex, a region associated with impulse control and moral reasoning. When their brains are less active in these regions during the same moral or impulse-control tasks, this may help explain why they are more likely to behave impulsively and to lack empathy for other people.

There is also the amygdala, which sits deep inside the brain and isn't visible on this scan. Other research on psychopathy suggests the amygdala is associated with emotional response, particularly fear. People with high levels of psychopathy tend to experience very low fear and are poor at aversive conditioning — the process by which punishment teaches us to avoid a stimulus that went badly last time. In people with high levels of psychopathy, the amygdala tends to be both smaller and less active.

So there are real neurological differences between people with high and low levels of psychopathy.

If someone has these dark triad traits, can they be cured? Some change is possible—but "some" is the operative word.

Most of the research on psychopathy in particular comes from incarcerated criminal offenders, who are required to take part in some treatment while inside. The research finds they're not particularly motivated to change, and that's a big problem: because they don't care about other people, and it's other people they hurt with their behavior, their attitude is essentially "why would I change? This is a you problem, not a me problem." So motivation is hard to come by with this population. That said, if they do consistently engage in cognitive behavioral therapies, you can reduce the likelihood of recidivism—that is, reoffending upon release. Again, we're talking about incarcerated individuals.

When it comes to lower levels of these traits, there's really interesting research by Nathan Hudson that had people do agreeableness challenges—agreeableness being roughly the opposite of these traits. Participants were pinged on their smartphone every day with small tasks: give a compliment to a friend, reach out to a friend and offer encouragement, buy coffee for the person behind you in line at the cafe. These little things encouraged people to be kind, be helpful, and see other people's perspectives. Those who actually followed through did report lower levels of these traits after four months than at the start.

In the book, under the "hard truths" section on dark personalities persisting, I write:

Poisonous people aren't likely to change very much. Personality traits are by definition enduring. Although some evolution of our character happens naturally, it takes decades. Data suggests that people become a bit more agreeable over time, and research with incarcerated men finds that even those with clinical levels of psychopathy are less likely to reoffend as they get older. Even so, waiting it out is likely to be a painful strategy.

One study asked more than a thousand people who had known a psychopathic individual for a long time whether their behavior had improved past age 50. Almost all respondents—93%—said, as the researchers put it, the behavior was just as bad or worse after age 50 than it had been previously.

It's their personality, right? It's like asking a tiger to change its stripes. If they're not motivated—and people with these traits tend not to be—that's where that 93% comes in. They're not dramatically changing unless they find some reason to do so.

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Asked what else in this research area is worth covering, the guest described her lab's current focus: how we respond to people who are lying to us when we're not suspicious at all. Most deception research gives people a set of videos, tells them some are lies and some are truth, and asks for judgments — but that's not how real life works. Nobody announces that you must judge someone's veracity; you're just having a conversation.

She has been studying how interactions unfold when one person is lying and the other is none the wiser, and keeps finding small but consistent effects: people feel less close to their interaction partner when that person is lying to them.

In one study, pairs of strangers simply conversed. One person was told to lie in response to everything; the other had no idea. At the end, the pairs containing a liar reported feeling less connected to each other than pairs where both people told the truth. Separately, the more people self-report lying in everyday life, the lonelier they feel — a bidirectional effect.

For the average person, most lies are pro-social: told to spare someone's feelings. But those lies create social distance rather than closeness, which is why she's interested in the negative impacts of lying even for "good" reasons.

Asked what drives this feeling of disconnection, she explained that liars are perceived as less warm, less competent, and less moral. Conversations also depend on reciprocal exchange — I tell you something about myself, you tell me something about yourself, and we start to know each other. A liar gives you less information about themselves, so you don't feel you know them by the end. Even without active suspicion about their likes, interests, or what they did on Friday afternoon, it comes across — you may simply conclude they didn't really want to talk to you.

Asked about other questions her lab has pursued, she described a study on how much sympathy people feel for those lying or telling the truth about how sad they are. Using the televised pleaders discussed earlier — people appealing for help finding a missing loved one, half of whom were actually responsible for that person's death — participants unaware that some were lying watched the videos and rated their sympathy and how much they would donate to a theoretical GoFundMe supporting the search.

The results were consistent: people were more willing to donate to genuine pleaders than deceptive ones, and felt more sympathy and compassion for them — without knowing some were deceptive murderers. The effects aren't gigantic, but they suggest we're not completely clueless moving through the world. The problem is that reducing it to a simple binary — is this person lying or telling the truth? — loses the nuance of how we actually navigate relationships: feeling closer to one person than another, being more willing to help one than another.

Host: Vanessa Van Edwards talks about warmth and competence—how overindexing on warmth might diminish perceived competence, and vice versa. Through your research, can someone be warm and competent simultaneously, or is there an inherent trade-off? And what does it actually mean to be a "warm" person?

Guest: Warmth is the perception that someone is kind, honest, and trustworthy; it reflects having benevolent intentions toward others. We trust people when they exhibit both warmth and competence: you need to believe someone wants to be kind to you, but also that they have the ability and competence to execute—such as making a valuable connection for you at work. If someone is warm but lacks the capability to follow through, people tend to trust them less. Consequently, high warmth combined with high competence is strongly associated with high trustworthiness.

Host: Does high warmth correspond to specific behaviors?

Guest: Yes. Basic cues include smiling and making eye contact. Much like the research by Alison Wood Brooks, it involves demonstrating active engagement and interest in your conversation partner through "immediacy cues"—leaning in, paying close attention, smiling, and maintaining eye contact.

Host: What about a stern resting face?

Guest: When we have very little information about someone, we rely on subtle non-verbal cues and body language to assess them. If an initial glance catches a slight scowl, it signals anger, which reduces perceived warmth and trust.

The interviewer asked what other fascinating questions the lab has pursued. The speaker explained that after finishing her PhD, she had been studying psychopathy and wanted to move away from thinking about murder all the time. Shortly after the Bernie Madoff Ponzi scheme collapsed, she realized business school could offer a new context for studying the same personality traits. She was also drawn to the notion of "successful psychopathy": since the earliest descriptions of the condition, there has been a suggestion that these traits can actually help you succeed. People often tell her, "That's terrible behavior, but sometimes it helps, right?" Her response: "Does it? What does the data say?"

She worked with Dacher Keltner to study whether psychopathic personality traits could increase influence in government and earnings as a hedge fund manager—two hyper-competitive contexts where these traits might plausibly shine. In government, backstabbing and backroom deals might win co-sponsors for your bills; in finance, a willingness to take risks and cut people or companies down in public, without worrying about hurting others, might pay off. She predicted these were situations where people high in psychopathy could excel; Dacher predicted they wouldn't.

Consistently, the data sided with Dacher: high levels of psychopathy were associated with less influence in government and less money as a hedge fund manager—a counterintuitive result for most people.

Narcissism and Machiavellianism: It Depends on How You Define Success

Some research suggests narcissism and Machiavellianism can be associated with rising through the ranks and perhaps earning a higher salary, but they are not associated with teams doing well. Most of the research, however, focuses on psychopathy. People high in psychopathy talk a good game and convince others they are great tactical and strategic thinkers, but if you ask how good they are at their job, they admit they are terrible managers: they bully subordinates, create enormous stress on their teams, and their teams have worse outcomes as a result.

Narcissists Look Like Leaders—At First

Narcissists tend to come across as leadership material early on. A study by Del Paulhus showed this nicely: student groups worked together throughout a term, and after the first meeting everyone rated each other on likability, confidence, intelligence, and agreeableness. The narcissists made a great first impression—they seemed to know what they were doing, appeared confident, and seemed willing and able to lead. But as the term went on, opinions shifted: this person is actually hostile, doesn't do the work, and is a pain to deal with.

What makes narcissism look good at the outset is our confusion of confidence with competence. When someone says they can do something very confidently, we assume they've got it—but saying it confidently is not the same as actually being able to do it.

Do Performers Have More of These Traits?

Asked whether actors or stage performers tend to have higher levels of these traits, she said not to her knowledge. The closest connection would be training in the Stanislavski technique, where an actor genuinely recalls and re-experiences an emotion rather than faking it; that kind of training might help someone mimic emotions. But she knows of no research showing that actors are higher in these traits either way.

The host presents a set of real dating profiles and asks whether dark personality traits can be spotted just from the wording and clues.

Ryan — chief of staff, Washington DC

His profile reads: "Professionally trained to argue my point. So, yes, I'm probably going to win the debate about what to have for dinner." That immediately feels like a red flag. "Savvy, strategic, and persuasive by trade" sounds very much like Machiavellianism — controlling the situation, being a smooth talker. "Savvy" suggests someone who is controlling you, perhaps using information to get you to do what they want. "Strategic" points to the strategic social style discussed earlier: unlike the impulsive behavior typical of psychopathy, this person is playing three-dimensional chess to get what they want.

The rest of the profile — exploring the city, great food, travel, "looking for someone who makes me laugh" — contains words that could serve as euphemisms for Machiavellian traits: savvy, strategic, persuasive — essentially "I can get anybody to do anything because I'll manipulate them into it."

These could be red flags, and he could still be a perfectly nice guy, but they are things to carry into a conversation: does he seem cynical about people, power hungry, willing to manipulate others to his own ends and step over people for what he wants?

The host notes that the closing line "makes me laugh" feels self-serving — you're asking for something for yourself. Everyone wants that, but whether you'd actually write it is another question.

Haley — lawyer

"My friends call me hurricane, but you can call me Haley. Equal parts chaos and good company." "Chaos" immediately raises potential psychopathy because of the impulsivity — you never quite know where she stands. In women in particular, psychopathy can be associated with volatile emotions and unstable closeness: seemingly very close one day, angry at you the next.

"I'll happily spend the weekend trying a new workout class or plotting a harmless prank on my friends" is a sadism red flag — someone delighting in other people getting hurt could be concerning. "Outspoken, tough enough to handle myself" also fits, since toughness is associated with psychopathy, and "Do you think you can handle me?" doubles down on it.

David — brain surgeon

"Surgeon by day, theater enthusiast and cocktail appreciator by night. I'm confident enough to pick the restaurant, self-assured to admit when I'm wrong (occasionally). My friends would describe me as the life of the party." These are potential narcissism cues: loves attention, "life of the party," confident he won't be wrong about the restaurant, and the bracketed "occasionally" suggesting you might not see much admitting of being wrong at all. "Don't worry, I'm sure I can find the time for you somewhere" with a winky face implies you might not be a priority.

Again, these are narcissism vibes to watch for in conversation: does he ever ask anything about you, or is the whole conversation about him and how fabulous his life is?

A dating profile is essentially an advertisement, not an entire person's personality — you can gather more information over time — but these are some red flags.

Chad — law enforcement, Texas

He's barbecuing in his picture, which feels on brand. "Looking for my wife who will join me for life. No debt and no kids. Don't worry, ladies, I'm housetrained. When I'm off duty, I'm very independent. You'll find me hunting outdoors, grilling, or challenging my buddies, looking for someone genuine to share life's adventures with."

The verdict: seems okay — nice, even. The host jokes about wondering what he's growling.

If I were to go on a date with any of these people — Haley, Ryan, David, Chad — from the dating cards we just read out, what verbal and non-verbal cues would I look for, whether dating them or in a relationship, to figure out if they had any of these dark personality traits?

These are early warning signs you can look for:

• Interrupting without tolerating interruption. Do they interrupt you often but refuse to tolerate it when you interrupt? That points to impulsivity and a desire to dominate. People sometimes get excited and interject, but the real cue is getting quite angry when you interrupt them.
• Ignoring boundaries. Do they consistently ignore personal or professional boundaries? Say you're on a date and say, "I'd really rather not talk about my family right now," and they keep asking — "Tell me about your brother and this terrible relationship you have with them." They keep pushing even when boundaries are set explicitly.
• Weird calmness. This relates to psychopathy and a shallow emotional affect — they show no fear, sadness, or concern for others when you'd expect it in a conversation.
• Acting like an authority on every subject. That's the narcissism vibe: they know everything about everything and you know nothing — they need to be the authority.
• Impulsive, off-the-cuff answers. They aren't really thinking; they just say whatever comes to mind immediately — a sign of impulsivity associated with psychopathy.
• Coming across as tough, combative, or cruel. Psychopathy is associated with aggression, wanting to dominate people, and cruelty — and of course sadism.

Haley said she likes throwing pranks, called herself tough, and asked if we could handle her — so maybe that's sadism.

Yep. Exactly.

One more that's interesting: do they make intense eye contact, seeming to peer into your soul? Clinicians have noted that people with high levels of psychopathy tend to make really intense eye contact. Also, do they lack self-conscious emotions like embarrassment, shame, remorse, or guilt? A deficit in those is associated with psychopathy. Do they spend a lot of time talking about themselves and show much less interest in you? That's our old friend narcissism. And when others are struggling, do they find it enjoyable, annoying, or boring? Enjoying it would be associated with sadism.

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Two things stand out: dark personality traits are very common relative to the impact they can have on lives, and according to your book and some of the research, people don't tend to change. That leads me to the conclusion that we might have to figure out how to deal with these people — whether we work in a company, a team, or even a family. Looking at the stats around antisocial personality behaviors, roughly one in five people are going to be antisocial in some way, so we can't just hope to avoid them in our lives.

Everyone's got a story, I think, and people feel relatively powerless, because the approaches we tend to take when other people hurt us don't work very well for these individuals. Normally, when someone hurts us, we tell them that really hurt me, they feel guilt, and they might apologize. Or we punish them in some way, and that leads them to avoid the behavior in the future. These are precisely the things that don't really work with people with psychopathy, for example. So we're left asking, how do I deal with this? My tools are not working.

What's really powerful to know is that there are things you can do. We've got seven rules for dealing with people with dark personalities, and the first one is to establish clear boundaries.

I want to preface this by saying that setting out the rules is not a guarantee that they won't be broken. We've talked about how people with psychopathy tend to break the rules — that's a defining feature of that personality. But research suggests that establishing clear rules and making them explicit decreases the likelihood of selfish behavior compared to having no rules whatsoever.

In my workplace, we have a respectful workplace policy, and when I read it I thought, why do people need to be reminded of this? It seems so obvious. But there are really good reasons to have such a policy. One is that it makes very explicit how we expect people to be treated here, which decreases the likelihood that even people with moderate levels of these traits will violate the rules. And more than that, if they do violate the rules, you've got something written down — otherwise it's very hard to do anything about it.

In a relationship, you can make it really clear what's okay and what's not okay, and you have to tell the other person — it can't just be in your head. It can also help to read in a buddy: if you have a friend who knows what you want out of a relationship partner, what the no-goes are and which behaviors cross the red line, having someone who can tell you when your boundaries are slipping can be really useful.

One anonymous example comes to mind: a family with five children, where one member told me she is the only one who has maintained a boundary against an older parent with a track record of dark personality traits. Because she has always held that boundary against the father, he has almost left her alone and targeted the other four siblings instead — and those siblings are suffering because they have no established boundary.

The interesting point here is that the person with a boundary seems to be preyed on less by the narcissist or the person with a Machiavellian personality than those who haven't established one. If that's true, what is it about the psychopathic or narcissistic person that leads them to choose easier, boundaryless targets? Does that hold as truth, or is it just anecdotal?

Research does support part of this, mostly in workplaces: in workplaces with codes of fairness, people with high levels of these traits are less likely to keep a bunch of the bonus money for themselves instead of sharing it fairly among their team. So there's evidence that having rules in place increases the likelihood that they will follow those rules, relative to a no-holds-barred situation.

There's also research on how people with high levels of psychopathic traits choose whom to prey upon. Individuals who are not very assertive tend to be more likely targets — it's almost like they're picking the weakest of the herd. So asserting some boundaries can help keep you from becoming that target.

I was thinking about a guest I interviewed on this podcast who had gone through domestic violence. She described the love bombing process by which this individual broke down her boundaries and her confidence over time, and then isolated her from her friends and family. He wouldn't allow her to call her mom, and would give her a script to follow when her mom called. One of the remarkable things I observed is how, over time, they had broken down her confidence in order to seemingly control her.

Is this a common practice?

Yeah, in domestic violence situations. It reminds me of the emerging research on gaslighting, where someone makes their partner doubt their sense of reality—correcting them all the time: "You're being too sensitive. You don't see the truth around you." What's so insidious about that is that it makes you dependent on the other person. And then the isolation can really decrease your ability to get out of it, because you don't have someone else who can check your sense of reality—that you really are seeing, feeling, and remembering things that really did happen, even though they're telling you it didn't.

What is gaslighting? Because we throw the term around all the time. The minute someone lies, we say, "You're gaslighting me."

It's a pattern of denying someone's version of reality. You might tell people they shouldn't be feeling the way they're feeling, that things didn't happen the way they remember them happening, that they can't trust their own perception of reality. It can be incredibly destabilizing and isolating. What's worrisome about it is that we really need other people to help us see reality. If we're only seeing it through their lens—if our own eyes and our own memory can't be trusted—we start to depend on their perception, which is essentially a control tactic.

Research does suggest that people with high levels of these traits endorse these tactics. They don't see anything wrong with doing that to a romantic partner, which would probably follow that they'd be more likely to engage in it.

A lot of romantic arguments would sound like gaslighting under that definition. Go back to the cheating example: suppose I said last Friday I was doing something dodgy, and you suspect I'm lying. So you say to me, "No, you weren't, Steven. You weren't at the office till 3 a.m." And I go, "Yeah, I was. I was at the office. You don't know what you're talking about, Leanne. You weren't there. You're making this up in your head."

Who was gaslighting who there? You denied my reality, and now I'm denying your reality. Wait—but were you actually at the office?

Does it matter? I'm trying to figure out which one of us was showing gaslighting behavior there.

I think it would be like if I say, "I feel insecure. I feel threatened by whatever you were doing on Friday," and you're like, "No, you don't. You shouldn't feel that way. There's no reason for you to feel that way. You're blowing things out of proportion." That's essentially denying my actual experience—that I feel threatened. Even if I might be wrong about it, that is my experience.

So I could deny the facts, theoretically. I could say, "No, at 2 a.m. I was falling asleep at my desk."

You could maybe argue with the facts, but it's when you start arguing with someone else's perception of reality—of their own subjective experience—that you stray into gaslighting.

In the example from my guest, that's exactly what happened to her. He started hiding her stuff in places. He put her car keys in the fridge to make her feel like she'd gone crazy.

That's absolutely bonkers. Okay, that makes sense. So back to what I was getting at with establishing clear boundaries: do they try to erode those boundaries, or do they leave you alone?

They're likely to try to push on them, but less so than if you have no boundaries at all.

The next rule is: don't give them power over others. All of these traits are tied to power—Machiavellianism is essentially named after the pursuit of power, psychopathy is associated with domineering people, and narcissism says "I'm better than you, I'm a born leader." People with these traits tend to be very interested in having power over other people, but research shows this does not go well for those working underneath them.

At work, employees under a boss with more psychopathic traits report being more stressed out. They're also more likely to bring that stress home, which creates more family conflict—so it spreads and doesn't stay where it is. These bosses tend to create division within teams and increase turnover intentions: if you're working for a boss with these traits, you think, "I've got to get the hell out of here," and you churn through staff. So giving them power over others is not a great way to deal with them, even when they want it.

Find win-wins using their actual motivations

There are other things you can give them that they do want—this is negotiating 101. You can look for win-wins, recognizing that what motivates them toward that win-win might not be what motivates you.

Imagine you have an employee who is bullying his subordinates, and you tell him he really needs to treat his team better because they're so stressed out—they're going home crying to their spouses and getting sick because of it. You're trying to make him feel compassion to get him to behave better toward his team. That's not motivating to him. It might motivate other people, but people high in these traits are callous and not concerned about others.

That doesn't mean they can't do something kind or helpful—they might just do it for a different reason. If the team is suffering under this bullying management style, you could say: "You've got this sales bonus coming up, but your team is so stressed out that you're not going to meet the target and you're not going to get your bonus. You need to treat your team differently." Money—they like money. They like power and status. It's not that they can't behave better; they might do it for a different reason.

The next rule is: use the carrot, not the stick. People, particularly those high in psychopathy, are very reward sensitive but not very punishment sensitive. You can try to punish them, but literally their brains don't process punishment the same way—they don't develop the link between "if I do this behavior, then fear of punishment." They're more likely to repeat the behavior than people low in these traits. So punishment has its place, I suppose, but it won't be as effective with these personalities in particular.

What's a huge missed opportunity is that we don't use the carrot when it's so powerful. Sometimes people say, "They're a bad person, I'm not going to reward anything they do—I won't give them any positive feedback because I think they're terrible." But if they do something kind, honest, or helpful, reward them. Reward them not with power over others, but maybe with a bonus at work or a job title, because they really care about status—that's a reward they'll genuinely like, and it increases the likelihood you get more of that behavior in the future.

Some people listening might be thinking: shouldn't you just fire these people? Shouldn't you get anyone with sadism, narcissism, Machiavellianism, or psychopathy out of your life entirely?

Given that a reasonably sized minority of the population has some elevated level of these traits, you're going to be cutting out a lot of people. They might also genuinely have really useful skills that you want in your company, so you need to learn how to manage this personality trait. Even with a low tolerance for these traits, you won't be able to completely avoid them at all times—and it might not be your decision to remove them.

Exactly. It might be a person you want to have a relationship with even if that relationship isn't perfect. Maybe it's a brother-in-law: he's such a pain in the ass, but you see him twice a year and you don't want to cut him out, because that means not seeing your sister anymore—and you love and want to support your sister. The stay-or-go question is just so complicated, with so many reasons why you might not be able to leave. So we need to learn the skills to manage interactions with these people as well.

Emphasize your common identity

People with high levels of narcissism aren't particularly interested in being fair or kind to you, but they are interested in loyalty. There are fascinating studies where researchers simply tell people things like "you have the same birthday" or "you have the same fingerprint type"—which I don't even think is a thing—but when people believe they share some commonality, those with high levels of narcissism get less angry when given negative feedback.

So start the conversation with what you have in common—maybe with that uncle at Thanksgiving who's always combative and talks about himself all the time: "We went to the same university. We root for the same football team." You establish "we are one," and then if you need to say, "You really need to pick up your game and help with the care of grandma," he might be more willing to listen instead of just reacting to negative feedback. People with high levels of narcissism don't like that, so emphasizing your common identity can help tamp it down.

Neuroscientist Tali Sharot has looked extensively at disagreement by placing participants in brain scanners to observe neural changes when they disagree. In a recent meeting, someone repeatedly opened counterarguments with the phrase "I completely disagree." Research across social psychology, behavioral economics, and linguistics shows that opening a rebuttal with explicit adversarial phrasing like "I disagree" actively hinders persuasion. Starting a counterargument this way triggers psychological resistance in the listener's brain, undermining their receptivity.

This pattern also applies to dealing with domineering bosses or individuals with high narcissistic traits. If you approach them aggressively about an inefficient workflow—such as complaining that three separate forms should be consolidated into one— they perceive it as an ego threat and shut down entirely.

Instead, phrasing the feedback as a collaborative question—such as, "What do you think if we turned these three forms into one form?"—softens the critique. While it does not guarantee immediate adoption, asking a question makes domineering personalities far more receptive and opens the door to co-creating a solution.

Become a detective and notice their cues. We know that these personalities tend to lie a lot—being manipulative and telling lies is part of their playbook, and that's what all these traits share. So the key is knowing what the cues of deception actually are: we're not looking for gaze aversion or fidgeting. We're looking for a lack of verifiable details, relatively few details, and signs of cognitive strain—and maybe following up when we start to see some of those signs.

red flags, and finally, avoid face-to-face negotiations. This is a really simple move that can be really helpful. Research out of the University of British Columbia had people with various levels of these dark traits engage in a negotiation—just over the price of concert tickets. What they found is that whenever those negotiations occurred face to face, the person with high levels of psychopathic traits or any of these dark traits got a really good deal; they were able to command a whole bunch of money for these concert tickets. Whereas if they engaged in the negotiation over text, that wasn't the case.

So if you need to negotiate with someone, these dark traits can be really domineering, and sometimes superficially charming in person—you can let your guard down and they'll take advantage of you. If you reduce them to words on the page, they lose some of that charisma. But there are also other practical reasons: you've got a written version of what was agreed upon, so you can't be gaslit later into thinking you're misremembering what was agreed. And you've got some time to think about how you want to respond.

If violence is a concern—say this is a domestic violence situation where you have to get out of the house and maybe negotiate some sort of settlement in a divorce—being face to face can be dangerous. Text literally puts physical distance between yourself and the other person. So there are all kinds of potential upsides: if you have to negotiate, pop it into text or chat as opposed to sitting down face to face.

I was thinking about all the things linked to just having a bit more time, but also the medium of text itself. One thing that came to mind is that if someone does have those dark personality traits, they're probably more cautious about what they say if it's permanent and written. If I was sending you an email, I might say something to you in person—but would I write that same thing in an email?

The other one is that in written form, you as the person on the receiving end have time to show it to other people and get another perspective—even putting it into AI, asking Google, checking if the facts are right, or asking your husband or partner if this is appropriate behavior.

Totally. Involving other people can be so helpful. Research suggests that whenever we discuss with other people before making a truth–lie judgment about someone else's statements, we tend to be more accurate. And whenever we're making judgments about someone's personality, if we're talking as a group, we tend to be more accurate. In another study, Dacher Keltner talked to a bunch of girls in a sorority and asked them who gets talked about the most in gossip, and also had people rate their personalities. It was the more Machiavellian girls who were talked about the most.

Talked about positively or negatively?

Negatively. We sometimes hear about whisper networks too—like "stay away from that guy at work." I would caution against just believing everything you hear in the rumor mill. But sometimes people spread information about their experience with a person, and we can learn from other people's experience before having to go through it ourselves, if we pay attention.

The three final cards here cover common mistakes people make when dealing with dark personalities.

The first is believing there's nothing you can do. Some of our go-to responses when people hurt us—trying to make them feel badly, trying to make them apologize, trying to punish them—don't work so well. But we've also talked about all the things you can do, so we don't need to feel completely helpless.

Another mistake is assuming they have the same inner experience as you. When trying to figure out what motivates people—as we discussed with negotiation—what motivates you to do a thing might not be what motivates me. I need to try to get into their head, figure out their goals and what would motivate them to change their behavior in this situation, then frame the interaction that way: convincing them to change for that reason, not because I think they should or because I would feel guilty doing what they did.

The last mistake is thinking you can change them. If your ultimate goal is to stick around expecting them to become kind, honest, super conscientious and helpful all the time, never breaking any rules, we need to be clear-eyed about the likelihood of that happening. Instead, we should deploy strategies for making our day-to-day interactions a little more positive, rather than just hoping that someday they'll wake up with a different personality.

What is the most important thing we haven't talked about that we should have, as it relates to your work and what might benefit listeners in their lives?

I think it's a matter of numbers. We've talked about how about 10% of people generally agree with the items we use to measure these traits, which means 90% generally do not. I want people to keep in perspective that 90% of people are good, kind, honest, and not breaking the rules.

But that 10% isn't causing just a little harm — they're causing hugely outsized harm. With respect to psychopathy, about 1% of the population has clinical levels of it, and offenders with clinical levels of psychopathy account for about 50% of all serious crime. These people are doing incredibly outsized damage.

We feel this in our own lives too — not necessarily in criminal rap sheets, but we all have that one person who constantly makes things hard because of these traits, causing strife at work or abusing people at home. If we can learn to mitigate the damage from this relatively small group, we can dramatically improve our lives, our workplaces, and our day-to-day interactions.

We have a closing tradition on this podcast where the last guest leaves a question for the next guest, not knowing who they're leaving it for. The question left for you is somewhat relevant — I like that you got this one: what is one great lie we've all been told?

I think one great lie we've all been told is that to be successful, you have to be in it for number one — that you need to exemplify these traits to get that promotion, to get that raise, to run that company worth millions of dollars. I actually went searching for evidence of that, to show that people with high levels of psychopathy could use their callous, cunning fearlessness to make more money as hedge fund managers. And I found the opposite. Even in the areas where we think these traits lead to success, they fall short. Really taking other people with us, and thinking about success as prestige — respect and care and concern from other people — is a much truer version of success.

Leanne, thank you so much. Thank you for writing a book that is incredibly illuminating — research-based while also unbelievably engaging. These subjects are so pertinent to everybody listening, and I know they're going to love this conversation, because much like you were when you started your career, we're all just trying to figure out the ultimate barrier and opportunity that sits in front of us: other people. As you articulated nicely earlier, we go through the world thinking everyone else's internal experience is a mirror of ours. It's very easy to get frustrated, or to feel like you're the problem or you're inadequate, if that's the lens you take to life. Through your research, you do exactly what you said — in a weird way, you make us more empathetic, maybe more optimistic, and less cynical about the nature of human experience. This is a wonderful book for anyone who wants more information; I'll link it below: Poisonous People: How to Resist Them and Improve Your Life. It might also be a good opportunity to buy it for someone else you know who is dealing with a slightly poisonous person. Where do people go to support your work and find more from you?

You can find the book wherever books are sold. You can also find me on Instagram, Leanne TenBrinke, on all the socials — TikTok, YouTube. I post little things about studies and findings that I think are interesting, and hopefully you'll find them interesting too.

Thank you so much.

Thank you, Stephen. This has been so wonderful.

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