Practical analysis for investment professionals
16 August 2012

Lie Detection for Investment Professionals: A Summary of Lying and Deceit Behaviors

With more than 100 scholarly papers to her name, Bella DePaulo, visiting professor of psychology at the University of California, Santa Barbara, is a preeminent authority on lying and deceit behavior. In her book, The Hows and Whys of Lies, the Harvard University–trained researcher provides a thorough overview of the results of hundreds of lying and deceit behavior studies. Here is a summary of her major conclusions.

  • A review of 253 samples in which truth detectors were shown equal numbers of truths and lies found that the accuracy rate at detecting lying and deceit behavior was only 53%. This result is extremely similar to the 54% lie detection accuracy rate found by Dr. Maria Hartwig and Dr. Charles F. Bond, Jr. in their paper “Why Do Lie Catchers Fail: A Lens Model Meta-Analysis of Human Lie Judgments.”
  • Ambivalence on the part of someone being questioned seems to be an especially strong indicator of lying or deceit. Again, this result is similar to that found by Hartwig and Bond.
  • People, when listening, often properly identify a lie, but when asked to commit to an assessment they do not listen to their intuition, thus nullifying the accurate assessment (Hurd and Noller 1988).
  • Additionally, truth detectors report feeling more confident when hearing the truth than they do when hearing a lie.
  • When talking for long periods of time, liars have a higher pitch than those who are telling the truth.
  • Liars take a longer amount of time to respond to a question when asked.
  • In general, liars are less talkative than truth tellers.
  • If liars have had time to prepare their answers, they respond to questions faster than truth tellers.
  • If liars have had less time to prepare their answers, they respond to questions slower than truth tellers.

Here is an overview of behavioral cues along with their correlations to the presence of lying behavior. Due to space constraints not all of the behaviors listed can be explained. DePaulo’s book contains further details.

Rank Behavioral Cue r
1 Cooperative −0.66
2 Pitch (when motivated) 0.59
3 Verbal & vocal immediacy (impressions) −0.55
4 Nervous, tense 0.51
5 Admitted lack of memory −0.42
6 Pupil dilation 0.39
7 Blinking 0.38
8 Talking time −0.35
8 Related external associations −0.35
8 Nervous, tense 0.35
11 Makes sense 0.34
12 Rate of speaking 0.32
13 Verbal immediacy (all categories) −0.31
14 Verbal & vocal uncertainty 0.30
14 Detailed response 0.30
16 Spotaneous corrections −0.29
17 Nervous, tense (overall) 0.27
18 Vocal tension 0.26
19 Chin raise 0.25
19 Logical structure −0.25
21 Foot or leg movements −0.24
22 Plausibility −0.23
23 Verbal & vocal involvement −0.21
23 Word & phrase repetition 0.21
23 Complaints 0.21
23 Pitch 0.21
27 Presses lips 0.16
27 Fidgeting, general 0.16
29 Eye contact −0.15
30 Illustrators −0.14
31 Foot/leg movements −0.13
32 Facial pleasantness −0.12
About the Author(s)
Jason Voss, CFA

Jason Voss, CFA, is a content director at CFA Institute, where he tirelessly focuses on improving the ability of investors to better serve end clients. He is the author of the Foreword Reviews Business Book of the Year Finalist, The Intuitive Investor. Jason also ran a successful blog titled What My Intuition Tells Me Now. Previously, Voss was a portfolio manager at Davis Selected Advisers, L.P., where he co-managed the Davis Appreciation and Income Fund. He holds a BA in economics and an MBA in finance and accounting from the University of Colorado.

Ethics Statement

My statement of ethics is very simple, really: I treat others as I would like to be treated. In my opinion, all systems of ethics distill to this simple statement. If you believe I have deviated from this standard, I would love to hear from you: jason.voss@cfainstitute.org

9 thoughts on “Lie Detection for Investment Professionals: A Summary of Lying and Deceit Behaviors”

  1. robinhood says:

    Why people often properly identify a lie, but when asked to commit to an assessment they do not listen to their intuition?

  2. Hi RobinHood!

    A great question. I have my own theory on that, but I am not aware of research that supports my theory. My theory is that people ignore their intuition because most of modern education is about rational/analytical decision making and we ignore, as information, things that easily described by either numbers or words. So a vast sea of information and feedback from our world is ignored, not because it doesn’t exist, but because we have over developed a limited number of ways of describing it.

    With smiles,

    Jason

  3. E. Emilov says:

    Thanks for the article!

    In the behavioral cues table is it a mistake that “Nervous, Tense” is mentioned twice but with different correlations, once at rang 4 and once at 8? Or am I not reading it right?…

    Completely agree on your theory about the intuition and education.

    On the other hand I think it could hardly be ever supported by a research as researches are by definition, quantifiable, limited and most of them originate in the same educational system that would make people ignore their intuition.

    Regards,
    E.

  4. Hello E.,

    You win the “nice catch” award, but not for the reason you may think. The above chart is a summary of decades worth of research and some studies have tested for the same behavioral cues but had different results. However, the very data point that you highlighted – nervous, tense – had the wrong sign. I mistakingly put it in the chart as -0.35, when, in fact, “nervous, tense” is positively correlated with lying/deceit behaviors.

    As for testing intuition…it is difficult. However, the studies that have been done have been in a laboratory-like setting where the researcher knows which statements being communicated by a test subject are lies. Additionally, to increase the level of stress felt by a test subject who is asked to lie/deceive often times economic incentives are provided such that if they are caught they do not make as much money. Don’t worry, the monetary amounts are likely not signficant enough to cause a permanent change in the behavior of the test subject.

    Thanks again for your catch!

    Jason

  5. Shehzaad Batliwala says:

    Do you think it is actually possible to quantify all these behavioral cues and ascertain whether a person is lying or not based on statistics created through test observations? It is given in the article that the accuracy of lie detectors is only about 50%. Then we might as well go for a heads or tails coin toss since the probability over there is also 50%. Every time we find a new observation or a new “behavioral cue”, a lot of those figures are going to change. What I am trying to say is aren’t we just trying to justify things with numbers after we’ve seen some observations, rather than creating concrete frameworks which would hold true and be able to predict correctly? And this thing is not possible, which I am sure, even you would agree. Thus are all these attempts futile?

    Regards

    Shehzaad

  6. Hello Shehzaad,

    Thanks very much for your comments, you have identified the very point I have made from the beginning of this series of articles on lying/deceit behaviors.

    Please check out the entire series of these articles that I have been writing – as you have hit on the very point I have been trying to make. People, even trained professionals, are no better than chance at detecting lies based solely on behavioral cues. That is a point I have made from the very beginning and thank you for highlighting it.

    With smiles,

    Jason

  7. E. Emilov says:

    That is if you are not Dr. Cal Lightman, of course. 🙂

    Just a joke.

    With respect,
    Emil

  8. T R says:

    I worry that using these small correlations would lead one to trust a calm, low-pitched liar and I would expect that those who lie the most are much better at presenting themselves than others. It is an interesting subject, but I will still be double-checking essential information regardless of the demeanor of the source.

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