How Often Do We Lie?

by | May 10, 2018


“A man is never more truthful than when he acknowledges himself a liar.” – Mark Twain

How often do we lie? A lot. And probably more than you think. More on the frequency with which we lie in the 2nd half of this IFOD.

In the past six months I’ve read two books involving honesty and lying: Everybody Lies: Big Data, New Data and What the Internet Can Tell us About Who We Really Are by Seth Stephens-Davidowitz and The Honest Truth about Dishonesty: How We Lie to Everyone – Especially Ourselves by Dan Ariely. I would highly recommend both books and a few key takeaways from them, as well as other research, is below.

A common theme of these books is that we (including you and me) lie a lot more often that we’d like to admit to ourselves. Dan Ariely makes a good point that most everyone “fudges just a little bit” on many things. Pretty much everyone view themselves as honest. It’s hard to tell big lies and still maintain our self-perception as honest, but we usually can tell little lies and preserve our sense that we are honest people. Additionally, we often deceive ourselves so we don’t even really believe we aren’t entirely truthful or have justification for why our little lies are ok. It is really this self-deception that is the source of our lies.

Evolutionary biologist Robert Trivers has proposed that self-deception evolved as a way to allow us to lie more effectively to others; if we believe our lies then we sound and act credible and our lies will be undetectable. Similarly, from Dan Ariely’s book: “Psychological studies show that we quickly and easily start believing whatever comes out of our own mouths.”

A great example of how we all fudge a bit is the “matrix test” example from Dan Ariely’s book. The experiment worked like this: a control group of students at MIT was given 20 math problems that were simple, but time-consuming to solve. They were told they’d be paid $0.50 for each correct answer and were given 10 minutes to solve the problems.  When time was up they were given the answers and told to turn in their test sheets and tell the proctor how many they got correct. The average number correct was four. Given that they turned in their answer sheet, cheating was not possible.

The experimental group was the same situation with one major difference: they were told to put their answer key through the shredder before telling the proctor their answer. So, they had an easy opportunity to cheat with no way of being caught. What happened? The average correct rose from four to six. There was nobody who said they got 20 correct. Pretty much across the board the students reported more correct than the control group. Thus, everyone fudged a bit. They probably said to themselves “I meant to put that answer on number 5” or “I was about to get this one right when time was called.” Etc.

Interestingly, when the Matrix Test experiment was repeated with awarding $10 per correct answer (versus the $0.50 in the original experiment), the control group still got four right on average but the experimental group self-reported five correct. So, when more money was at state the students found it more difficult to justify cheating and still feel good about themselves.

So, how often do we lie each day?

A study published in 2010 from Michigan State used a survey of 1,000 adults to see how often they reported they lied over the past 24 hours.  Here is a chart summary of the responses:


Only 40% admitted they lied at all in the past 24 hours! A small percentage admitted they told over 20 lies but most who admitted to lying only thought they lied one or two times. Question: who is more honest? The admitted liars or those who denied lying at all?  More on that below.

The study authors did note “An obvious concern with self-report, mass survey research is accuracy of reporting. Given the pervasive cultural prohibitions against lying, self-presentation motives favor under- rather than over-reporting [of lies].”

In the book “Everybody Lies” mentioned above, Seth Stephens-Davidowitz notes that “people have no incentive to tell surveys the truth” but their search habits on Google reveal who people really are and our Google searches (as a country) tell a very different story about who we really are than we tell surveys (or our friends or family or ourselves). There is a big gap between who we present ourselves and who we really are. Here’s a thought experiment. Would you rather have a copy of your tax return published on the internet or your Google search history?

How much do we really lie? A few studies that are not surveys tell a different story. A study conducted in 2002 at UMass Amherst engaged 121 pairs of students in a one-on-one casual conversation for ten minutes. They were told the study was to “examine how people interact when they meet somebody new.” Unbeknownst to the students the conversation was videotaped. The students were then asked to watch the videos of themselves and identify any “inaccuracies” they had said, no matter how big or small. The students were shocked at their number of inaccuracies they spouted during a ten minute conversation. Sixty-percent of the students identified at least one lie they told during the ten-minute session and those who admitted to telling a lie averaged three lies during the 10-minute conversation! Compare that to the 60% of adults when surveyed who thought they told no lies within the past day.

More on frequency of lying:

  • USC psychologist Jerald Jellison determined that people are lied to about 200 times a day.
  • Charles Honts, a professor of Psychology at Boise State University and polygraph expert believes that humans lie in about 25% of their social interactions.
  • A British video rental service determined that about people lie about having seen films that they haven’t actually seen. Most notably, the company determined that 30% of the people claiming to have seen The Godfather actually had not seen the movie!

Don’t believe the above findings on how much we lie? Try paying attention to everything you say. Notice how much of what you say isn’t completely factual. How often do you fudge the truth? Even when it doesn’t matter? I’ve been doing this for a few weeks. It’s sobering.


  1. Can I have the resource for this study? Thank you!

  2. In gathering the data I think we can assume that an understatement (excess modesty) counts the same as a great exaggeration. That would make the amount of lies not seem so bad.

  3. Wow, this ia a good one. It’s possible that someone who never lied and was completely honest….might be seen as belligerent.
    A question, ” How are you doing?” often is a platitude or way of saying, “I’m nice, dont be mean to me.”
    But an honest answer could be: ” Well, I’m mad that I have to see you. I dont like you and wiah you would stop acting like such a phony! Leave me alone! Blah blah blah.”
    The “lie” back that might be better received could be: “I’m fine, tha k you for asking. Hope you are too, have a good one!”
    Basically, being Nice & Friendly may make a society and social interaction much better, while lying at these times make make the world a depressing place.
    These lies are ones we are often encouraged to participate in…
    Anyway, thanks for the great article John. I learned a lot, and enjoyed your thought you put into it! 🤥…no really!


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