I had something of an epiphany tonight building on an earlier thought after listening to a true crime podcast: Polygraph tests are the pickles of the true crime genre. Unless you like pickles, which by the transitive property means you like polygraph tests, in which case, I’m going to at least make the argument against one of those.
It astounds me that somehow in the year 2022, I’m still listening to true crime podcasts that include polygraph tests, much like how by default, my sandwiches and other items will come with pickles even though I don’t like pickles! Instead, the default, if you’re dabbling in the true crime genre, ought to be either a.) disregard polygraph tests completely as junk science and dangerous junk science at that; and b.) if you are going to mention it, you better spend an awful lot more time talking about how they are junk science rather than a valid piece of evidence.
Similarly, pickles are junk (not junk food), but I digress.
There is no machine yet devised by man that can accurately, or at least to some approximation of accuracy, measure the veracity of a human being’s statements. There is no science involved in the polygraph test, or how there more colloquial name, lie detector tests. As the American Psychological Association notes, at best, these machines are “inferring deception through analysis of physiological responses to a structure, but unstandardized, series of questions.” Emphasis is theirs. In other words, that isn’t science, and I certainly do not trust police departments still utilizing polygraph tests to administer them in anything approaching science. But let’s even push that aside momentarily and zero in on “physiological responses.” I don’t trust that as a measurement of lying, either. In general, someone being questioned by the police — and please get a lawyer; never allow yourself to be questioned by the police without one! — is likely to experience some measure of physiological responses that differ from their baseline physiology. That doesn’t mean they are concealing or lying. It doesn’t mean they are a criminal.
Passing a polygraph test means nothing and indicates nothing about whether someone is telling the truth about a crime. Likewise, failing a polygraph test means nothing and indicates nothing about whether someone is telling the truth about a crime. And perhaps more importantly, someone (rightly!) declining to take a polygraph test does not evidence their guilt or an attempt to conceal their guilt.
The silver lining here is that the United Supreme Court in U.S. v. Schneffer largely ruled against polygraph evidence as being admissible in court due to their unreliability. The case actually wasn’t criminal in the way we tend to think about it — it was about a United States airman who passed the Air Force’s polygraph examination asking him whether he used drugs since enlisting and then a urinalysis later found the presence of methamphetamine; the airman then faced a court martial — and Justice Clarence Thomas found that the military’s Rule 707 serves the legitimate interest of ensuring that only reliable evidence is introduced and that “there is simply no consensus that polygraph evidence is reliable.” (So, Rule 707 prevented the polygraph examination results from being admissible.)
In my state of Ohio, a polygraph-induced (I even hate that phrasing) confession is admissible “so long as it is voluntarily, knowingly, and intelligently made.” I can’t imagine anything going wrong with that (heavy sarcasm). Not to belabor the point, but we know too much about false confessions generally and false confessions induced by polygraphs to trust the system in that regard. For more on the latter, the Innocence Project documented a number of cases of false confessions via polygraph in Chicago here.
Get the pickles out of my sandwiches and please get the polygraph tests out of the true crime genre. And unlike with pickles where I’m more than happy to share them with someone willing to allow them into their mouths, you can feel guilt-free (heh) in tossing the junk science of the “lie detector” out.
And someone applaud me for making it this far before remembering to make a Maury Show joke because I, for one, will not be the father of propagating such silliness in anything true crime I write about.