It’s lunchtime in Brighton and a group of people are sitting around a table at an outdoor seating area outside of an office building. I ask if they mind telling me about a time they fudged the truth. This is not an easy task. 

Most people are not willing to regale a stranger with their past indiscretions. The only person at the table to come forward was a 20-something-year-old guy named Brian.

“I took my friend’s dog to the dog park the other day.  And he happened to get into a fight with another dog,” said Brian. “And when we came back, he asked how things went, and I said they were fine. Because really, how’s it going to help anything if he finds out that he got into a fight?”

What’s interesting about talking to people about their dishonesty is hearing how they rationalize it.

I guess I wouldn’t really consider it a lie because it’s not like I told him — I mean outside of that, everything did go fine. So I just left out the part where things weren’t fine,” Brian said.

Brian didn’t necessarily tell a lie, so much as omit a part of the story. But he wasn’t entirely truthful. Which isn’t necessarily a bad thing, according to Joe Tecce, a professor of psychology at Boston College.

Omitting vs. lying

Lies of omission generally are not as harmful as lies of commission, generally speaking,” Tecce said. “And if you unveil all the truth all the time to the person you live with, aren’t you going to create a lot of stress in their life?”

Tecce is a lying expert. He has devoted years of research to the detection of deception through body language, such as blinking and hand gestures. He said we rationalize our lies in order to feel less guilty as a protective mechanism.

We’re on this planet to survive. That’s the first and most basic instinct of human beings-- is to survive. And therefore there are some lies that are intended to survive,” Tecce said. “For example, President Clinton, young Billy Clinton avoided being beaten by his alcoholic stepfather Roger by lying with what I call a protective lie. He didn’t always tell the truth, or else he’d get beaten.”

When it’s OK to lie

There are several nuances of lying and Tecce has put them into categories. There’s the “protective lie”—for safety or to spare someone’s feelings. The “heroic lie” is when someone takes the fall for another. Ad example of the “ego lie” is when someone says, “I’m the one who ended the relationship.”

There’s a playful lie,” Tecce added. “You know, I caught a 3 foot long fish, and then it got away…who who is that hurting? It’s not hurting anybody-- unless the person gets in the habit of lying all the time. And there we have probably one of the most serious disadvantages of lying. That’s when a person lies enough and is not able to discriminate inner reality from external reality.”

Back at the outdoor seating area in Brighton, there’s a table with two guys, and one of them, Sean, tells me about his most recent indiscretion.

I’m starting a new job in two weeks. And during that negotiation they ask you salary and bonus. I think I might have rounded up on a couple instances,” Sean said.

In this case, Sean lied.

Which ended up helping me in the long term because the new company was able to go a little higher so I got a larger jump than I would have if I told them exactly what I was coming in at,” said Sean. “I think when you’re negotiating for a new role, for a new job, I think there’s certain negotiation tactics you need to do in order to get what you want.”

Let’s be honest—that’s a pretty common lie. Joe Tecce says that falls into the “protective lie” category. But even then you’re not off the hook.

Avoiding boomerang justice

In the short term if you lie about your salary, your resume, people do that a lot-- you got to undo it a little bit later on,” Tecce said.

By undoing it, he means…tell the truth.

Make an effort to undo it later on by retracting it or telling the person, you know, you might have said this a little bit differently. And in that way, we have the best of both worlds,” said Tecce. “We have lying for survival, but not lying to ruin the fabric of society. Our society is based on trust. Relationships are based on people telling the truth.”

What you don’t want is for that lie to come back and haunt you. Some may call it karma, but Tecce calls it “boomerang justice.”

“Because there is a certain magic about boomerang justice.”