Why are some people pathological liars? Experts explain.

Dice with letters that spell fake and fact
Experts say pathological liars tend to be immature and may have low self-esteem. (Getty Images)

New York's George Santos is set to be sworn into the House of Representatives this week, but his political career is already tainted by controversy. Santos has both admitted to and been accused of a slew of lies about a range of things, from his education and work history to his religion.

Santos told the New York Post in late December that he fabricated parts of his résumé, including claims that he graduated from college and that he was once employed by Goldman Sachs and Citigroup. Santos also said that his family had a real estate portfolio of 13 properties and that he needed to leave a private school he attended after his parents fell onto hard financial times, but he later told the Post that was also falsehood.

“My sins here are embellishing my résumé. I’m sorry,” he told the Post. Santos also once said that his mother was Jewish and that his grandparents escaped the Nazis during World War II. Now he says that he’s “clearly Catholic,” but says his grandmother told stories about his family being Jewish and converting to Catholicism. “I never claimed to be Jewish,” Santos told the Post. “I am Catholic. Because I learned my maternal family had a Jewish background I said I was ‘Jew-ish.’”

Despite calls for his resignation, Santos has vowed to serve his constituents. “I intend to deliver on the promises I made during the campaign — fighting crime, fighting to lower inflation, improving education,” he told the Post.

Santos has been accused on social media of being a pathological liar, but why might someone lie to such an extent — especially when they can so easily be caught?

“All humans lie,” Dr. Hillary Ammon, a clinical psychologist at the Center for Anxiety & Women's Emotional Wellness, tells Yahoo Life, pointing out that “most people occasionally lie to avoid undesirable consequences, such as avoiding conflict, punishment or hurting someone else’s feelings."

But a pathological liar “often lies for no reason, with no clear benefit,” Ammon says, noting that the lies are “often grandiose and over-the-top.” Pathological liars are “often good storytellers” and that “sometimes they start to believe their lies.”

Lying can spiral, Ammon says, pointing to one study that suggested that the more people tell self-serving lies, the easier it becomes to continuously lie, as a result of changes in the brain.

Some people are more prone to be pathological liars than others.

There's not always a clear reason why someone might be a pathological liar, and anyone can regularly lie, clinical psychologist Dr. Thea Gallagher, a clinical assistant professor at NYU Langone Health and co-host of the Mind in View podcast, tells Yahoo Life.

However, people who are pathological liars tend to be immature, Dr. John Mayer, Chicago-based clinical psychologist and author of Family Fit: Find Your Balance in Life, tells Yahoo Life. "They have undeveloped cognitive abilities such as low IQ, and they have some degree of sociopathy," he says. “Sociopathy is a deficit in the following, understanding and recognition of social norms of behavior. These conditions may have developed because of a childhood trauma, poor parenting environment, poor social environment where lying is a survival necessity at times.”

Some pathological liars may have low self-esteem “and lie in an attempt to feel more satisfied with themselves and be perceived more positively by others,” Ammon says.

Pathological lying can be a sign of a mental health issue.

It's important to point out that being a pathological liar on its own isn't considered a health issue. "It's not a clinical disorder — it’s more a symptom of a larger problem,” Gallagher explains. However, she says, being a pathological liar could be a symptom that someone is struggling with one of the following mental health conditions:

  • narcissistic personality disorder

  • antisocial personality disorder

  • borderline personality disorder

“While there isn’t extensive research on the causes of pathological lying, there are studies that show relationships between habitual lying and head injuries, imbalances in the hormone-cortisol ratio and central nervous system abnormalities,” Ammon says.

Signs of a pathological liar

Because this isn’t a clinical diagnosis, there aren’t a set of confirmed symptoms of being a pathological liar. However, experts say the following can be signs that someone may be a pathological liar:

  • Stories or previous accomplishments are often over-the-top, illogical or not feasible.

  • Stories may change when someone is questioned about them.

  • The person is defensive about their stories.

  • The person deflects answers about stories when questioned.

“They tend to do a great deal of explanation of their actions — use a lot of words and provide way too much detail,” Mayer says. “They take ownership of events — for example, you may have participated in something or even been the major player in it, but when the pathological liar tells the story, they tell it as if they are the center of everything.” This, Mayer says, is a key indicator of pathological lying.

Pathological liars will also lie about “unimportant, small, minor things,” Mayer says.

There is no set treatment for pathological lying, and the motivation for it can be obscure. Gallagher says she's treated people who have struggled with the mystery of it. “I have some patients who say, ‘I don’t even know why I’m lying, but I am,’” she says. “If that describes you or someone you love, it might be important to unpack that with a therapist.”

Ammon agrees. “Once the underlying factor is understood, people can work on that issue in therapy, in addition to reducing lying habits,” she says. “Habitual lying can have a negative impact on a person’s relationships, job and sometimes even cause legal implications. Therapy can also be useful to work through these challenges.”

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