Over at FiveThirtyEight, there is a nice rundown of the research on detecting liars. “[R]esearch suggests,” it reads,
our interpretations of testimony like Kavanaugh’s, or Christine Blasey Ford’s earlier on Thursday, will be shaped by what we already believe. The Kavanaugh confirmation fight and Ford’s allegation that he sexually assaulted her are taking place in a political context, tapping into partisan identities. But even without those particular biases, humans just aren’t very good at reading people. And that’s why testimony is “no substitute for a good, solid, thorough investigation and finding of the facts,” said Brian Fitch, a psychologist and retired Los Angeles County sheriff’s lieutenant.
In other words, we were never going to get a better idea of whether Kavanaugh was telling the truth by watching him speak. (He’s denied all the allegations against him.) That’s just not how the human brain works, said Judee Burgoon, director of human communication research at the University of Arizona. That’s because our ability to identify a lie is poor — no betterthan chance, in fact. “The best estimate, and that’s from a lot of studies all accumulated, is that we’re about 54 percent accurate,” she told me. “That’s about equivalent to flipping a coin.”
Both she and Fitch said that there’s no twitchy tell, no revealing behavior, that is indicative of lying or truth-telling. Partly, Fitch said, that’s because behavior is culturally mediated. When we all live in the same culture, people who want to lie know what behaviors might make them look more or less credible, as much as the people who are watching for those behaviors.
How about people who are supposed to detect lies, like judges, police officers, or custom agents? “Studies show they believe themselves to be betterthan chance at spotting liars. But the same studies show they aren’t, Alcock said. And that makes sense, he told me, because the feedback they get misleads them. Customs agents, for instance, correctly pull aside smugglers for searches just often enough to reinforce their sense of their own accuracy. But “they have no idea about the ones they didn’t search who got away,” Alcock said.” It also turns out that “it’s possible to interview someone in a way that creates inconsistencies and credibility issues that weren’t there originally. Because of this potential, there have been efforts to change the way law enforcement officers conduct interviews, particularly of people from vulnerable groups, including victims of traumatic violence.” What’s more, political “bias probably plays a big role in situations where we’re testing the trustworthiness of people under politically charged circumstances, and some studies have shown that it can have as strong an impact as the biases we carry related to race.”
The article concludes,
Given what we know about how humans interpret the behavior of other humans — and how bad we are at doing that accurately — it should be no surprise that there appears to be a strong partisan split in how both politicians and regular people viewed Kavanaugh’s testimony. In fact, Burgoon said, this is why you generally want more layers of information in an investigation. You’re not going to learn the “truth” based on somebody’s body language. “I think that’s part of the desire for an FBI investigation, because the FBI would produce a more impartial rendering,” she said. Indeed, Republican Sen. Jeff Flake, a crucial swing vote, asked on Friday for the full Senate vote on Kavanaugh to be delayed a week so that the FBI could produce just such a rendering. Of course, as Burgoon added, not everyone is going to believe the FBI’s findings either.
If you generally identify on the political left and found Ford’s testimony “credible” or if you generally identify on the political right and found Kavanaugh’s testimony “compelling”, then there was likely nothing credible, compelling, or rational about how you came to that conclusion. 1 It was more likely political hooliganism in action.