If you didn't grow up in an emotionally-dysfunctional family (and you should know that makes you a pretty rare person!) - then your ability to accurately read other people's true feelings from their facial expressions should be pretty good.
If you grew up in a dysfunctional family where your safety and / or well-being depended on being able to read people's true feelings accurately, then your ability to accurately read other people quite possibly borders on the supernatural. (More on this another time, but researchers have found that a lot of the people who were physically beaten up as children, if they didn't get completely emotionally 'wiped out', actually developed super-sensitive abilities to read other people, and to sense their true feelings.)
If you grew up in a dysfunctional family where you had to pretend 'everything is fine', and that 'everyone is happy', and that 'it's all good' - even when it definitely wasn't, then this post is really for you, because your ability to match emotion to facial expression got disconnected in that environment.
You felt like someone was angry, (correctly...) but they told you they weren't. You felt as though someone was unhappy / stressed/ scared / panicked etc - but they told you they weren't.
So now, you probably have no clue about how the people around you really feel, and even more problematic, you probably have very little clue about how you yourself feel. But help is at hand. Ekman has put together a course that can teach you how to accurately read other people's emotions, and particularly what he calls their 'microexpressions' in an hour.
Here's how his site describes the different types of expressions that appear on a human face:
TypesMacro: normal expressions usually last between ½-second and 4 seconds. They often repeat, and fit with what is said and the sound of the person’s voice.
Micro: These are very brief, usually lasting between 1/15 and 1/25 of a second. They often display a concealed emotion and are the result of suppression or repression.
False: A deliberately-made simulation of an emotion not being felt.
Masked: A false expression made to cover a macro expression.
For months, I've been looking for the word to try to accurately describe the expression on a certain person's face who really creeps me out and upsets me. One look at this page on Ekman's site solved the mystery for me: it's contempt!
It struck me that if more of us could figure this stuff out just by glancing at someone's face, it would make life a heck of a lot easier to know who and what we're dealing with. Ekman also has a number of books that you can buy on Amazon, and I highly recommend taking a look, because micro, false and masked expressions are all around us.
People's characters really are written all over their faces, just we don't always know what we're looking at.