Rep. George Santos continues to face blowback, public protests, legal investigations and new accusations after it became apparent that he had told a collection of lies about his background while campaigning to represent parts of Queens and Long Island in Congress.

Unless Santos, who was sworn in over the weekend, is charged with a crime or he steps down, he’ll likely keep his seat, if the history of the nation’s legislative body is any guide.

But his Pinocchio-esque tales leave one to wonder how a person can fabricate so much of their backstory and release it to the public over and over again.

Is someone who may have lied, repeatedly, about major details of his life story a pathological liar? What is a pathological liar, exactly? We consulted with psychologists, political scientists and a neuroscientist to make some sense of lies. Here’s some of what they had to say.

Who lies?

Just about everyone.

Teenagers tend to lie the most, and most of us get more honest as we age. We lie to get what we want, and that could be anything: to make a friend feel better about their new bangs, to avoid a teary confrontation with a child or to get ahead at work.

On average, people tell one to two lies a day. But that number is itself a little sneaky, because many of us go through a day telling zero lies. A small group of outliers – about 5% of society according to multiple academic studies from psychology experts – brings up the average. These mega-fibbers offer up deceptions about five times a day or more, with the extreme liars telling about 15 lies a day.

Do people want to lie?

No.

“Deception's almost never a goal – it’s a tactic for achieving some other goal,” said Dr. Timothy Levine, a distinguished professor and chair of communication studies at the University of Alabama at Birmingham.

“If I can flatter you honestly, I'll flatter you honestly,” Levine said. “I only need to flatter you deceptively if I'm having non-flattering thoughts about you.”

The same applies with bigger lies, he said. A used car salesman might lie regularly for a paycheck — but give them a better product to peddle, and they might start telling the truth.

If people feel bad when they lie, why keep doing it?

One theory is that we can get used to lying.

Part of what curbs dishonesty is that most of us feel mental discomfort when we lie, according to Dr. Tali Sharot, a cognitive neuroscience professor at University College London who directs the Affective Brain Lab.

“If you take that out of the equation, people are more likely to lie,” Sharot said.

She, along with three other scientists, examined what happens to brain activity when we lie and published their work in 2016. When the subjects first started fibbing, the researchers observed strong activity in brain regions associated with emotion, which could indicate discomfort. But, as the subjects continued lying, the response decreased. Essentially: they became habituated to lying.

Can people believe their own lies?

Yes. It’s called the “illusory truth effect,” Sharot said.

The more we hear something, the more we tend to believe it. This concept applies to the truth, disinformation – even our own lies.

So someone who, say, seems to have lied about his life story, work history and more, is a pathological liar?

Not so fast.

The term “pathological liar” is often used interchangeably with “prolific liar.” Both groups of people lie a lot.

But pathological lying is “more of a compulsion,” said Dr. Drew Curtis, who runs the Curtis Deception Lab at Angelo State University in San Angelo, Texas.

Last year, he, along with psychologist Dr. Christian Hart, co-authored Pathological Lying: Theory, Research, and Practice. Curtis said that they see pathological lying as a distinct mental disorder, characterized by telling a large number of lies (10 daily on average) that impair function, causing danger to the liar or others. Pathological liars typically feel remorse for their untruths.

“Some CEOs or psychopaths or maybe even politicians may tell excessive lies, and there is no remorse. There is no distress,” Curtis said. Therefore, he said, he would not consider them pathological liars.

How many people are pathological liars?

Curtis and Hart estimated that about 5% of the population — one in 20 people — are pathological liars. It’s hard to say, because pathological lying isn’t in The Diagnostic and Statistical Manual of Mental Disorders (DSM), the standard bearing text for the field of psychology that gets updated every few years. Curtis said the disorder was referenced by several prominent psychologists over 100 years ago, but they called it different names. Also, the early DSMs didn't have as many classifications as you see now.

Without its inclusion, there isn’t a common set of criteria for mental health professionals to use and diagnose people with these characteristics. Currently, pathological liars are most likely to be diagnosed with antisocial personality disorder, which includes deception as a characteristic.

Why would people believe a politician who may have lied about his religion, his resume, and more?

“Of course they did,” Levine said. “Who would lie about that?”

“Our normal default state is to believe what people tell us because most of what people tell us is true,” Sharot said.

In other words: We’re wired to assume others are honest. That’s usually a good thing because it would be impossible to get anything done if we had to first investigate whether everyone — from the barista to our life partner — was lying to us all the time. The downside of this standard bias toward believing people is that sometimes we get duped.

Also, we tend to believe things that are ordinary-sounding because they take less brain power to process, Sharot said.

Someone who states they have a rainbow cat might trigger a “surprise signal” in the brain, she said. But someone who fibs about working at Goldman Sachs or having Jewish ancestry?

“From what I understand, it's not like he was saying something that sounded really bizarre,” Sharot said.

Do we usually know when we’re being deceived?

Alas, no. Humans are not very good lie detectors. A study led by Dr. Kyle Mattes, associate chair of politics and international relations at Florida International University, found that when people watched short video clips of political speeches, they correctly detected lies only about half — 52% — of the time. This result means they fared only slightly better than pure chance.

So what does an expert in the field of deception make of a politician who lied about his resume, his religion, his education, and more?

“I'm really curious,” Levine said. “Was this somebody who was super desperate for success and they felt that this was the only way they were going to be able to do it? Or were they a compulsive person [for whom] things got spun out of control?”