Imagine this. The jury has just been instructed that they are the judges of credibility, and are told to pay close attention to witness demeanor during testimony. Then, the witness arrives and takes the stand, wearing a niqab, the Islamic face-covering that leaves only the eyes exposed. "Great, so what are we supposed to be observing?" the jurors think, "How can we tell if she is truthful or not?" That is the thinking that has led some judges in several countries, including the U.S., to not allow testimony from a veiled witness. For example, in one case, a plaintiff's complaint was dismissed after she refused to remove her veil in order to testify (Muhammad v. Enterprise Rent-A-Car, 6-41896-GC, 31st D. Mich., 2006). But the belief that a veil makes it impossible to assess credibility turns out to be flat wrong.

In a study recently published in Law and Human Behavior (Leach, et al., 2016), researchers from Canada and the Netherlands asked study participants in those countries, as well as the UK, to evaluate the truthfulness of mock witnesses under different conditions. Testifying female witnesses were randomly assigned to be veiled or not veiled, and were randomly assigned to either tell the truth or lie. Then the researchers asked the study participants to assess whether the witness was being truthful or not. The result was that the study participants were more accurate when witnesses covered the head (hijab) or all but the eyes (niqab), than they were when the witness was unveiled. The title of the study, "Less is More," suggests why: The authors theorize that in removing visual distractions, the veiled condition forced study participants to focus more on the verbal content of the testimony, and that verbal content ends up being more reliable in determining truthfulness. The important take-away here has to do with more than just hijabs, niqabs, and burkas: It speaks to a misplaced and sometimes dangerous faith that we can place in nonverbal communications.

The Research

Lie detection is notoriously difficult, and no small amount of study has been devoted to that problem. The present study (Leach, et al., 2016) had the more narrow purpose of looking at whether courts are correct to require an unveiled face during testimony, or whether those prohibitions just reflect a now-dated belief that untrained judges and jurors can reliably look at someone's facial expressions to see if they are lying. In correspondence with Psyblog, lead author Amy-May Leach noted that, in contrast, it was only the veiled witnesses who were able to be correctly identified as truthful or lying at rates better than chance. "Contrary to the assumptions underlying the court decisions cited earlier," she wrote in the article, "lie detection was not hampered by veiling across two studies. In fact, observers were more accurate at detecting deception in witnesses who wore niqabs or hijabs than those who did not veil."

The Implications

These findings don't necessarily translate into advice for witnesses to adopt the veil. Indeed, as the authors note, there are strong stereotypes and biases that attach to muslims, and the veil itself could serve as a cue to generate misperception, fear, and avoidance. But the findings do have something to say about nonverbal communication. Specifically, I see three messages.

We Put Too Much Faith in Nonverbals

Lie detection is typically at or near chance levels, around 50 percent. Despite that, we tend to place an outsized faith in our ability to read nonverbal communication. Some in my field, in fact, trade on an ability to be a "jury watcher" and to convey to the trial team what jurors are thinking. But even trained observers can fall victim to stereotypes and assumptions when it comes to nonverbals.

That Faith Creates Interference

The veil oddly works to improve lie detection because it prevents interference. As Amy-May Leach explains, "Veiling of the witness might force observers to attend to sources of information that are more diagnostic of deception, such as verbal content." Pop psychology beliefs, such as the "Neurolinguistic Programming" chestnut that liars look up and to the left, can similarly interfere with better methods of assessment, like carefully listening to words.

Our Instructions are Dated, and Wrong

Instructions that focus on demeanor are still common. Trial consultant Cynthia Cohen, for example, recently observed, 'The Judicial Council of California Civil Jury Instructions suggests that jurors pay attention to demeanor in evaluating truthfulness. It suggests that jurors rely more on their visual assessments than on their notes." That appeals to common sense, but it doesn't square with the social science.