Recent weeks have seen various forms of evidence, rightly discredited by reformers for their tendency to mislead, being rehabilitated in the hopes that they might “get” Brett Kavanaugh. Politics has always featured cheap tricks and sloppy expressions of principle, but the sheer scale and promotion of these techniques in the coverage of the Kavanaugh case signal a dangerous trend. My point here is not to argue for his innocence or for his guilt, but to correct some misconceptions — the truth of which our political classes have seen fit to blatantly ignore. This is important because the legal system does not confine itself to one person at a time. Ideas and policies made popular here will have a ripple effect.
Polygraphs have featured heavily in the discussion because the accuser, Christine Blasey Ford, took one (albeit with a very unusual set of questions). And why shouldn’t they? We’ve all seen spy films and crime dramas with truth-detecting polygraphs, the scourge of the guilty, which only psychopaths have a chance to thwart; their efficacy is broadly accepted, much like the harmlessness of sugar or the fact that lightning never strikes the same place twice. The power of the polygraph is widely believed, and on a bipartisan basis. Jeff Sessions has called for their use in the White House as a way to catch leakers, and Kamala Harris highlighted Ford’s polygraph and Kavanaugh’s lack of one. There is, however, a hitch. Despite the senators’ endorsement, psychologists have argued for decades that polygraphs are built on pseudoscience, and the Supreme Court was aware of this consensus by 1998. The American Psychological Association noted in 2004:
Most psychologists and other scientists agree that there is little basis for the validity of polygraph tests. Courts, including the United States Supreme Court (cf. U.S. v. Scheffer, 1998 in which Dr. Saxe’s research on polygraph fallibility was cited), have repeatedly rejected the use of polygraph evidence because of its inherent unreliability.
Early theorists believed that deception required effort and, thus, could be assessed by monitoring physiological changes. But such propositions have not been proven and basic research remains limited on the nature of deceptiveness. Efforts to develop actual tests have always outpaced theory-based basic research. Without a better theoretical understanding of the mechanisms by which deception functions, however, development of a lie detection technology seems highly problematic.
Indeed, as of 2002, several infamous double agents who worked for the KGB, Chinese intelligence, and Castro’s Cuba had held high-level security clearances in the U.S., having passed regular polygraphs without an issue. It could be argued that the use of the polygraph in determining access was part of the problem, because this problematic source was treated as the arbiter of truth. FBI agent Mark Mullah woke to a nighttime raid on his home, which was followed by an investigation into every element of his personal and financial life and dismissal from his position, all because of a “positive” result on a polygraph. While his badge was returned after no evidence was found, the result destroyed his career and reputation. For all his anguish, an FBI agent, or for that matter a judge, still has some resources and contacts. Ordinary people suspected of crimes are often deceived by police into thinking that the polygraph is mandatory (in reality, you are never required to take one). They take the test and consequently get a “positive” result, because in reality polygraphs measure fear and anxiety — both of which are likely to be felt by an innocent person facing charges for some heinous deed.
That Senator Harris, a 1990s-style law-and-order former prosecutor playing at being a reformer, would make a spectacle out of dubious evidence is not surprising, but the uncritical boosting of Harris by journalists who should know better is troublesome. It may help to turn public opinion against Kavanaugh, but more concerningly, it amplifies the myth of polygraphs as lie detectors. The fact that Judge Kavanaugh spoke positively of polygraphs in his 2016 Sack v. U.S. Dept. of Defense opinion has been cited in favor of their use — but, simply put, he was mistaken. The science on the matter is clear.
Meanwhile, Elizabeth Loftus, a renowned cognitive psychologist, has spent much of her career studying the reliability of eyewitness testimony and the nature of memory. Her research was buttressed by exonerations that followed the rise of DNA evidence. Brandon Garrett, a law professor at the University of Virginia, noted in his book Convicting the Innocent that, of the first 250 innocents who were exonerated due to DNA evidence, 190 had been convicted based on incorrect eyewitness testimony. These eyewitness accounts were not vague statements, either. As Adam Liptak wrote in the New York Times following the release of the book:
Many of those witnesses were as certain as they were wrong. “There is absolutely no question in my mind,” said one. Another was “120 percent” sure. A third said, “That is one face I will never forget.” A fourth allowed for a glimmer of doubt: “This is the man, or it is his twin brother.”
As with polygraphs, the American Psychological Association has expressed skepticism about the use of eyewitness testimony. In 2011 it submitted an amicus brief laying out the problems with eyewitness testimony, including the effects of time on memories and the fact that “human perception does not work like a camera or video recorder. Rather, what is perceived and stored in memory is often incomplete or distorted as a result of the individual’s state of mind or the nature of the event observed.” They do not dismiss the use of testimony in toto, but emphasize that these issues with memory reflect the scientific consensus and should be taken into account when weighing evidence.
The accumulated research and exonerations have led several jurisdictions to carry out reforms in the use of eyewitness testimony. New Jersey’s Supreme Court has ruled that jurors need to be informed of the fallibility of eyewitness testimony and memory. North Carolina, Wisconsin, and several counties on both coasts have issued new rules to minimize the problems associated with eyewitness testimony. This has been a particular priority for reformers because, despite its inherent issues, there is something unquestionably persuasive about a person passionately making a case before judge and jury in person. This means that misidentification or other mistakes in eyewitness testimony can have outsize effects. Indeed, the Innocence Project calls mistaken identifications “the leading factor in wrongful convictions.”
Just as we saw with polygraphs, discredited science about testimony is now being called forward as an opportune tool for the political moment. The New York Times recently ran an op-ed by a psychiatrist, Richard Friedman, stating that
neuroscience research tells us that memories formed under the influence of intense emotion — such as the feelings that accompany a sexual assault — are indelible in the way that memories of a routine day are not.
Decades of research by thousands of psychologists are suddenly waved away in favor of an out-of-date view, because that view is politically convenient. This is the criminal-justice equivalent of citing Peter Navarro’s Trumpian rants against trade as representative of economic science. Navarro and Friedman technically do have credentials in their fields, but it is dishonest to portray their heterodox views as reflective of the mainstream — especially when these views have had such human cost.
The effect of boosting polygraphs and eyewitness testimony to the rank of irrefutable proof is not going to stop with the Kavanaugh hearings. It could, however, have a much more sinister effect. Through television, social media, and newspapers the general public is receiving the message that these types of evidence are perfect. The politicians who are advocating it as such are now on the record as having made that claim, which will make it difficult for them to support criminal-justice-reform legislation in the future, because they would look hypocritical. And those politicians who would still support reforms will find themselves subject to attacks for being pro-criminal, as opponents take advantage of the public’s misconceptions about evidence such as polygraph tests and eyewitness testimony.
If Kavanaugh is guilty, his nomination should be rejected, and if he is innocent, it should be accepted. But in the process of trying to “get” Kavanaugh, opponents must be wary of setting back progress in criminal-justice and policing reform. Whether they succeed or fail by doing so, thousands more — in the most marginalized positions of our society — will pay the price.