Recently there was a Supreme Court decision about whether people should be forced to expose their faces when testifying in court. This case originated with a rape victim who wore a niqab and was called upon to testify against her attacker.
One of the ostensible reasons given for wanting witnesses to uncover their faces is that facial expression are thought to be informative in assessing the witnesses' credibility.
But is this also the case with people who are accustomed to covering their faces? If a certain method of communication is never available to you, would you be able to use it - and use it in the way the audience is expecting - if it were suddenly made available? If you only ever used it in private and intimate settings and were suddenly called upon to use it in public, in front of an audience, and under scrutiny, how would your performance be read by people who use it every day?
I know someone who immigrated to Canada as a toddler. He learned English quickly and easily like one does at that age, but he also retains the language of the old country, which he uses to talk to his parents and such. However, because he left the old country at such a young age, he still speaks the other language like a toddler. He has a childish accent, and he's less articulate and nuanced than you'd expect of a successful adult. If he were called upon to testify in court in the language of the old country, his testimony would not reflect his actual credibility, because he's not accustomed to using that method of communication in the way the jury would expect. Similarly, I find myself wondering if the facial expressions of someone who normally covers their face might also fail to reflect their actual credibility because they aren't accustomed to using that method of communication in the way the jury would expect.
I myself don't have a very expressive face, and my natural inclination is to keep it neutral. When I was a kid, people would always say things to me like "You look disgusted" or "Don't glower at Mrs. Neighbour like that" when I wasn't intentionally doing anything with my face, or feeling any of those emotions being attributed to me. I later learned how to modulate my face in the way that's expected - a skill I was still mastering well into adulthood, because quite a lot of it I learned from Eddie Izzard - but it still isn't natural behaviour and doesn't come to me easily. It's like telephone voice or a firm handshake - a performance I can put on, but not a natural reflection of my thoughts and feelings. However, I'm not sure whether I'd be able to maintain the performance in so stressful a situation as testifying against my rapist, and if I can't maintain the performance my expressions may well be misinterpreted, like they were when I was a child, and be detrimental to my credibility through no fault of my own.
So if it could go so badly wrong for someone like me who has always been in a face-exposing culture, imagine how badly it can go to someone who isn't accustomed to their facial expressions being scrutinized and is suddenly having their credibility assessed based on something that they have never before had interpreted as informative!
I hope someone can actually do research and get scientific data on this, because the only thing I can imagine more terrifying than being forced to expose more of your body than you're comfortable with when testifying against your rapist is then having him set free and your credibility called into question because the jury is assuming you're more fluent than you are in a form of communication that you never use.