Over the years, finding a reliable form of lie detection has been the subject of much debate. Today I’m going to address the potential impact that improved scientific methods of credibility analysis will have on litigation.


There are some scholars who argue that using an expert witness to provide the jury with an opinion about a witness’ credibility removes the very point of having a jury in the first place. We all understand the value of experts. For example, without an entertainment industry expert, how could a jury determine the appropriate damages in the event of a breach of contract in the film industry? Without a construction expert witness, how could a jury possibly know if a building is in violation of a commercial building code?  In a wrongful death action, how would a jury analyze the life expectancy of the decedent and, by extension, the amount of damages to award?

But credibility is another story. So far.

From “truth serum” to polygraph tests to lie experts who analyze physiological micro-leaks consistent with deception, we have been looking for and in many instances rejecting, a means of bringing more science to the jury’s central job: finding the truth.  And we’re getting closer.

Neuroscientists are identifying more and more specific areas of the brain that respond in a scientifically consistent and predictable fashion when stimulated in various ways. Which neurons are firing when a person is being dishonest is not a matter of fact to be interpreted; it’s a matter of science. It’s only a matter of time, probably not even very much time at that, before scientists are able to determine with virtual certainty when a person believes he’s lying, and when a person believes he’s telling the truth.

I’m very careful how I describe what those neurons are actually telling us. When a person lies, in order for his brain to respond as though he’s dishonest, he must believe that he’s actually prevaricating. If he believes he’s telling the truth, as in an eyewitness who truly believes that he saw an event, even though he didn’t, his brain activity will be consistent with truth telling. And that’s appropriate, because not knowing that you’re wrong is not the equivalent of knowing that you’re lying.

Many people see this as a horrible invasion of privacy. To read a person’s brainwaves – isn’t that tantamount to reading a person’s mind?  And yet, it has a lot in common with taking a blood test or fingerprint analysis, too. The response isn’t being compelled; the person isn’t being forced to speak. It is an analysis of a physiological reaction, not a thought, but a brain wave. But somehow it sure feels close. Once it happens, it will be the closest that science has ever gotten to reading a person’s mind.  Creepy.

Yet, if litigation is about doing battle and finding the truth, then isn’t this an invaluable tool that we should use when it becomes available?

Ultimately, when science takes this step, and they will, it will be found admissible as soon as the general scientific community accepts the test.  And then the jury’s function will no longer be necessary in determining whether a witness believes he’s dishonest. That will be a matter of science. Instead, it will be reduced to determining when a witness is right and when a witness is wrong. For many purists, this is sacrilege. But to me, as scary as it is, I can’t wait. The more we know, the fewer mistakes we’ll make. And that’s a good thing, I think…

By: Ian Heller, Attorney at Law