Truth Matters

The way polygraphs are currently being used in politics, everyone loses.

Polygraphs are premised on the intuitive notion that truth matters so much, our own bodies and blood show it when we lie. Yet, lie detection is a myth. There is no unique lie response to detect, and so there is no lie detector. But truth matters. That’s why polygraphs should never again affect issues of national importance such as who works at the National Labs, who is suspected of forbidden dissent, who is sent to Abu Ghraib or sentenced to death in America, whose criminal complaint is investigated, how—or who is (or is not) granted a lifetime appointment on the US Supreme Court.

Whether the Senate confirms or derails Judge Brett Kavanaugh any day now, the junk science of polygraphs will have influenced the outcome of an important process in which it had no appropriate place. Democrats could succeed in blocking the nomination because they consider Kavanaugh’s first sexual misconduct accuser, Dr. Christine Blasey Ford, to be credible. That would be unfortunate in a sense, because Dr. Ford’s credibility was bolstered by passing a polygraph. But my National Science Foundation-supported doctoral dissertation research showed that polygraph chart interpretation is vulnerable to confirmation bias. That is, if people already have information about a subject’s background, that information can create an impression of what the truth is—and that, in turn, can influence how the polygraph chart is read.

(As a sidenote: This bias can be neutralized, my research shows. But no one seems to have applied the solution that I demonstrated. I don’t care, because the scientific consensus is that polygraphs are insufficiently evidence-based for any important uses in the first place. So it would be silly to invest resources improving rather than ditching them. But the way the overwhelming majority of polygraphs are conducted introduces possible confirmation bias that could be but has not been systematically addressed.)

Conversely, if the Republicans succeed in ramming the confirmation through before the midterms, the newest Supreme Court Justice will be one who knowingly let the executive branch lie in Court and bowed down to, instead of balancing, its abusive power. Judge Kavanaugh was the federal appeals court judge who denied me access as a researcher to polygraph program records that would have enabled further analysis for bias among other things.

The Defense Department told the court polygraphs were so important for law enforcement that their records must be kept secret, and Kavanaugh ruled as though he believed them. The fact that he openly believes polygraphs to be unreliable as a matter of judicial consensus when the stakes are personal suggests that he did not, when he ruled on my case, really believe the argument that DOD made.

That would be unsurprising, since DOD’s argument did not make sense. Kavanaugh’s subsequent ruling was also illogical, as analyzed here. The only explanation for the logical inconsistencies in both would seem to be abuse of power.

Some might say that it would be poetically just if polygraphs helped derail Kavanaugh’s nomination after he unjustly defended polygraph program secrecy. And yet, it would be so much more just if junk science did not affect important outcomes. If polygraphs were retired along with the misconception that real victims report sexual assault immediately to police, when they very often don’t. Never again to tip the scales of justice away from due process. Never again to cloud issues of great national political significance with pseudoscience.