When the news first broke that George Santos, the freshman Republican representative from Long Island, had lied on his résumé, my first thought was, Well, of course—he’s a politician. As the scope of the lies grew, however, my evaluation changed: not a politician, but a con artist.

It’s a difference that I’ve stressed repeatedly in the years since I published a book about con artists. Branding anyone who misrepresents something or lies a bit as a con artist might be convenient, but if we do so, the term loses all meaning. For con artists, lying is a way of being. It reaches past exaggeration or misrepresentation into a prevailing disconnect from reality.

Santos’s long list of fabrications brings to mind some of the most prolific con artists of the past century. His educational history is made up: no attendance at Horace Mann, as far as anyone can tell. No Baruch, no NYU. In fact, no college degree at all. Though you have to admire his penchant for specifics—top 1 percent of his (nonexistent) Baruch class! (For one of many historical analogues, see Ferdinand Waldo Demara, a.k.a. the Great Impostor. Demara, a high-school dropout, made a habit of claiming others’ credentials as his own, including Ph.D.s, M.D.s, and any other degree he could get a hold of.) Nor do Goldman Sachs or Citigroup have records of Santos working there. (For a historic tour de force of fake employment histories, see Clark Rockefeller—real name, Christian Gerhartsreiter—who was not only a fake Rockefeller but also a claimant to quite the nonexistent business pedigree.) And that’s merely a sampling of Santos’s lies.

[Read: Why Americans get conned again and again]

How does someone in the public eye ever hope that deceptions of this magnitude will go undetected? What explains con artists’ impulse to deceive, repeatedly, even as the fictions they tell become harder to maintain? These questions have fascinated psychologists for years—and we’re beginning to find answers.

In three years of research on con artists—interviewing them, spending time with them, submitting them to psychological questionnaires, and reading any available psychological literature on them—I found that con artists tend to exhibit some combination of the so-called dark triad of personality traits, which have been studied in deceptive behavior more broadly: psychopathy, narcissism, and Machiavellianism. Although psychopathy tends to get a lot of attention—few things are as eye-catching as the word psychopath—the trait that, to me, exemplifies the psychology of the con, and explains the hubris behind a pyramid of lies as high as Santos’s, is narcissism.

Narcissism in the case of the confidence artist is not narcissism in the sense that you and I might use when talking about someone who feels that the world revolves around them. It’s an almost pathological hubris; the thought that you haven’t gotten caught yet, so you never will get caught. The sense that, out of everyone, you deserve it the most, whatever it might be. True narcissism lets you rationalize all manner of sin; it’s self-delusion taken to an extreme.

Narcissism breeds, as well, a self-reinforcing cycle: The more you lie, the more entitled you feel—and the more qualified. In 2019, an international group of psychologists—Francesca Gino of Harvard, Wiley Wakeman of the Stockholm School of Economics, and Celia Moore of Bocconi University, in Italy—ran a series of studies that looked at cheating’s effects on self-image. Would people who cut corners on a task feel more or less confident in their skills afterward? The results were somewhat counterintuitive: Subjects who lied about their performance on a series of matrix problems actually felt more competent afterward. I must be good at this! Look at how well I did! (Ignore, for a moment, that I inflated my results.)

[Read: Can you spot a liar?]

The psychologists also went a step beyond the typical laboratory games to a pursuit more directly relevant to Santos: lying on a résumé. Participants were given a task—apply for a job using supplied credentials—and would receive a bonus if their application was deemed to be in the top 25 percent of all applicants. The trick was that each of the supplied credentials could be twisted or misrepresented, if the applicant so desired. Oxford Brookes University could become the University of Oxford. A two-week executive-education program at Harvard could become an actual degree from Harvard. And second-class honors could be inflated to first-class honors. A full 35 percent of participants chose to misrepresent themselves on at least one of their credentials—and the ones who did reported feeling significantly more competent at the end than those who had accurately conveyed their qualifications. It’s the extreme of dressing for the job you want—to the point where you begin to believe you’re more qualified for that job than those who worked for it.

The result is a perverse dynamic. The more a person like George Santos misrepresents himself and cons others for his own gain, the more entitled he feels to keep going. Why should I resign when I’m the most qualified for the job? The con artist, at least to some degree, comes to believe his own lies. One recent series of studies found that people who were confronted with evidence of self-deception—believing themselves to have performed better than they actually did, and better than the average person, on a series of trivia questions—not only failed to acknowledge their self-delusion but began to see others as the ones prone to it. (Cue Santos’s recent interview with Piers Morgan, in which the representative mostly deflected responsibility for his lies.)

Of course, it’s not enough to lie and justify your conning to yourself. You have to convince others to believe in you. I’ve argued that there’s a con for everyone: Not everyone will fall for every con, but anyone can fall for a con that’s well suited to them. The master con artist knows how to pick the right victims and the right venue—and then how to sell his story most effectively.

Here, Santos chose well. Politics is an area where shades of gray aren’t just tolerated; they are the norm. So if anyone ever catches you in a lie, it’s easy enough to explain it away. Add to that Santos’s choice of district—on Long Island, where there was little competition (he ran uncontested for the Republican nomination) and an element of time pressure (last-minute changes in the district-map lines thwarted would-be challengers)—and you have a perfect stage for even the biggest lies to go largely ignored.

[Caroline Mimbs Nyce: A resigned politician’s advice for George Santos]

Even in the ideal arena, how do you get others to put their trust in you? Con artists seem to intuitively grasp what psychology researchers know: We tend to trust people who appear and act similarly to us. (Some studies have grouped people together in relatively arbitrary ways, like whether they over- or underestimated the number of dots in a picture or whether they preferred art by Kandinsky or Klee, finding that participants were kinder to those they thought were like them.) Santos claimed to be Jewish, for instance, when he ran against Jewish opponents—and presumably wanted to capture that voter demographic. (He later claimed he had said he was “Jew-ish,” rather than “Jewish.”)

When all else fails, emotion, emotion, emotion. The more emotional we are, the more likely we are to give someone the benefit of the doubt and put our logic aside. Santos’s mother dying because of 9/11 was apparently false. Some of his employees dying in the Pulse nightclub shootings was also apparently false. His grandparents surviving the Holocaust, again, appears to have been fabricated. As Demara, the master con artist, once put it, Americans want to be liked more than they want to be right. We’d rather err on the side of sympathy than distrust. My heart goes out to the victim of tragedy—and if I suspect he’s making it up, I’ll keep it to myself.

Sure, there are calls for Santos to resign, and a House ethics investigation could be coming, to look into multiple complaints about his behavior. “A sick puppy,” Senator Mitt Romney called Santos at the State of the Union. And yet he’s still in Congress, head apparently not bowed in shame.