I like it, but the facial expressions are really silly..

You obviously didn't watch it close enough to see the "examples" of real life people/crooks and how the character's expressions for that episode matched. Either that or you are one of those odd birds that believes all politicians and the government and movie stars would never lie.

That's why they're micro-expressions . You probably do "grin like a wolf" to someone you dislike. You just don't know you're doing it, and it only lasts for a split second .

Facial expression recognition is not an exact science, which is why it can't be used as evidence in real life. This is a science fiction series (but it is reeeally cool and well made, I love this show). The examples of facial expressions shown throughout the show help build the notion that the protagonist is a very smart and educated person, but it isn't very hard to come to the conclusion that the creators of the show can display any face they like to examplify an expression.The detail we need to pay close attention to is the star (*) in the title.

Sorry if I ruined this for anyone... But I already knew this when I watched the pilot, and I have a great time watching this show. It reminds me a lot of House MD, which is also a scientifically ridiculous show. The illnesses and symptoms are real, but the procedures aren't believable. The same can be said for Lie to Me; the expressions are probably very real, they are just not scientifically reliable in the way shown in the show.

EDIT: I'm a cross-dresser (I like science as much as I like culture and philosophy), and I can't stress enough how BRILLIANT this show is. Love every second of the dialogue and the story! VERY impressive writing, directing and cutting!

Well, duh. There's also two really good reasons the micro expressions on this show are so easy to spot:

1) They have to be, because the makers want the audience to feel smart by making them feel like they can spot micro expressions.

2) The actors don't genuinely feel the emotions because, surprise surprise, they are acting. They have to simulate micro expressions which is hard if not impossible.

Here is a person to look up. Paul Ekman. I studied his work, learned Micro expressions and something not mentioned in the show, subtle expressions.
The METT & the SETT are both brilliant tools.

I agree, it's too obvious.

We see some guy scratch his nose. They zoom in on it and show it again in slow motion. Later the team review the video recording and point out how he scratched his nose. Then they show pictures of celebrities scratching their noses. A bit much?