Can you look at a person's face and tell if they have a psychological problem?

Yes. But I think this is really confirmation bias. “I just knew there was something wrong with that person! They had a strange look in their eyes.”

It’s complicated. Humans are extremely good at picking up on subtleties of facial expression. But exactly what expressions are considered appropriate—or “normal”—in different circumstances will be influenced by culture. We learn the language of facial expression, and we don’t all “speak” exactly the same version of that language. I could see plenty of room for misinterpretation.

If you’ve ever seen the movie “The God’s Must Be Crazy”, remember the scene where the bushman is brought to trial for having killed an antelope? He stands in front of the court with a fixed smile on his face, because that’s appropriate in his culture. But it seemed pathological to the court because they expected a serious or contrite expression.

Yes. I prefer not to make an instant judgment, however, most of my instincts have been spot on.

I can recall several situations where I knew the person was different in a big way.

One was a severe hoarder on one of our rental properties. I knew when I first saw her walking around, and the first time I said “Hi!”.

In that example, she was also a bit of a recluse, so her social differences were apparent.

Yes, it was an uncomfortable encounter.

Yes .. that can happen easily if you really look at someone when you’re talking to them. You can tell odd “affects” and facial expressions that just don’t match their mood or demeanor. I can imagine a cop would really need to have this “skill” since people aren’t always as they seem.

It’s a good and bad “skill” .. sometimes I’d rather not see the things I see… makes me a bit distrustful. I hope I’m wrong and I am sometimes .. but not often.

Only if they have a fork sticking out of their nostrils, or some other kitchen based blunt instrument.

Sure, if a person is certifiably deranged. However, I get a bit suspicious when people claim that they can read people and tell that a person has a psychological problem. You might be reading a mood, or a situational emotion, or a seemingly non-related medical issue. My wife can tell when my blood-sugar is low just by looking into my eyes. I met a guy who had that thousand-yard stare and then found out his son had died the previous day. My sister got incredibly paranoid for a few months and later discovered that it was related to a calcium deficiency. We might be able to tell that something is “odd” with someone, but I think it’s potentially dangerous to assume psychological issues.

I certainly have encountered people whose facial expressions told me there was something wrong with them. Many times behavior has confirmed it—assuming that I was not misinterpreting the behavior in light of a judgment I had already formed.

But when there’s no opportunity for confirmation, how do we know our judgment is correct? I always wonder when someone declares: “I can tell a(n) {addict | head case | abuser | homosexual | virgin | pregnant woman (before she shows) | religious fanatic | whatever} just by looking at them.” What sort of follow-up tests do they perform to find out if they’ve drawn an accurate conclusion? Never mind if it’s any of their business. Do they just assume they’re right—and does that then become a data point that they treat as real information the next time they meet someone with a similar appearance?

This is not to discount the virtue of instinct. And sometimes we just have to go on an instinct and act quickly—for example, to get away from someone who makes us uneasy. But acting on that feeling does not turn the act or the feeling into factual evidence.

My last husband was a police officer & he made people nervous, even if they had no reason (had done nothing illegal) to be nervous. In today’s society, getting stopped by police can be hazardous to one’s health – so it does not surprise me that @john65pennington has the ability to make people nervous & people being nervous can make other people think that they are hiding something such as mental problems. I think it requires more than a chance meeting to establish if a person actually has mental problems, unless the mental problems are so blatant that the person displays paranoia ( & having said that, just because a person thinks that someone is trying to kill them does not mean that someone is not trying to kill them ). If a person makes you uncomfortable, then walk away from them & do not try to engage them in conversation – but do not make snap judgements about their mental state, there are all sorts of reasons for attitudes that people display.

Maybe in the most extreme circumstances, especially when combined with their actions at the time. I think that one needs to tread lightly here, since I don’t think that too many people would enjoy being labeled in such a way themselves by others. I can usually tell when a person (or a group of them) will be trouble or not when I collectively observe their actions and demeanor along with their facial expressions. I usually call them ‘gut feelings’ though.