The Science of Lying

In middle school, I used to play those lie detector games with my friends, the ones give you a mild shock if lie. Obviously, a $5 toy doesn’t have scientific accuracy to lie detection. But, I’ve always wondered if there is actually a reliable way to tell if someone is lying beyond the tell-tale signs that behavioral analysts monitor.

When police interrogate criminals, they look for a number of signs to tell if someone is lying. These include repetition of the question, facial expressions, body language, comfort and charm, shifting stories, eye movement and blinking, and phrasing (McGauley, 2015). While these are all proven tactics, they aren’t 100% accurate. There could be outside reasons for a person’s strange behavior. Maybe they’re just nervous, which causes them to mix up their stories and fidget around.

This is why many scientists are working to measure brain activity while a person is lying. This would provide a more scientifically accurate determination of whether a person is lying. Some research involves positioning electrodes on various places around an individual’s scalp to measure the electrical signal on the brain’s surface as the person lies. They commonly ask the participant to choose one of two items and then claim to have neither. This way, they are both telling the truth and lying. The electrodes are flawed however, in that they can’t pinpoint the specific brain area that is activated since it measures such large areas of the brain at once. This is where functional magnetic resonance imaging (fMRI) comes into play.

fMRIs provide more precise reports of where exactly in the brain the activity takes place when someone lies. Lies activate many regions of the brain, but by measuring the blood flow changes that take place in the brain, researchers have been able to generally deduce that there is a spike in prefrontal cortex activity when a person is lying. This is further confirmed by previous conclusions about this area of the brain. The prefrontal cortex is engaged specifically in planning, the development of an individual’s personality, decision-making, and the way someone socializes (Good Therapy, 2013).

Admittedly, many everyday actions stimulate this area of the brain, but this doesn’t mean the procedure is useless. At this point, researchers, using fMRI detection methods, can accurately distinguish lies from the truth about 85% of the time (Curley, 2013). This statistic does not give rise to it’s official use however. The very rare instances where the tests were suggested as evidence in court, the results were quickly suffocated by opposition from neuroscience experts.

There are some obvious flaws that need to be resolved before fMRIs can be used in court cases and elsewhere. All the tests involve manufactured lies. Participants are instructed when and how to lie, and therefore don’t experience the same emotional stress as with a natural lie. Researchers also estimate that even when the lie is genuine, there may be ways to outmaneuver the machines with subtle movements and breathing control. fMRI technology isn’t yet ready to be applied to the real world, but I would guess that we’ll be seeing its use in the near future.


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3 thoughts on “The Science of Lying

  1. Peter Bott

    This post brought back old memories of the show The Moment of Truth where contestants were given up to $500,000 if they answered all 21 questions truthfully. The victims (contestants) were hooked up to a lie detector answering the 21 questions before the show was aired and would then answer the same questions again in front of their families. I always wondered how accurate the tests were and if the people could believe in their own lies so much that they would actually pass the test.

  2. Michael Robert Szawaluk

    I have always considered myself a fairly decent liar; when it comes to my parents anyway. Since I have gotten here I having probably been watching too much TV, and because I do not know how to work it, always find myself watching The Steve Wilkos Show. For those of you who do not know what that is you can find that here : The way they determine whether or not “you are the father” or “no, she has not cheated on you” has been through lie detector tests. And of course I wonder how can you cheat the system and how accurate can that thing really be. As it turns out lie detector tests can be pretty accurate; but check this website out with some interesting statistics:

  3. David Ross

    I have always found lying to be an interesting topic. On Netflix, I watch a lot of criminal mastermind shows that involve the main character getting out of even the trickiest situations, often by lying. I have even seen people manipulate lie detectors so that they can’t determine whether or not the person is lying. While of course this was all in a show on Netflix, I have always wondered if people can actually pass lie detector tests even though they lied for a majority of the questions if not for all of them. This could probably be answered by looking into the actual machine that performs the test and considering that the machines are about 85% reliable I am sure there is some way to cheat the system.

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