16/20, male. Definitely the eyes.
Male, 15/20.
Damn, that woman in #13 looks like she would scare Charles Manson!
F 16/20 the four I missed were genuine and I thought they were fake.
Female, 19/20.
I looked for the eyes and the way the people moved as they smiled. Real smiles tend to have eyes that look around, not just straight ahead, and the people move their bodies a bit.
No wonder they’re smiling.
As for me, Male; 17/20
Male. 18/20. I thought a couple of genuine smiles were fake. Judged almost entirely by eye crinkles.
Male, 17/20. I was surprised that I did so well, but as others said, it was in the eyes.
13/20. Male.
Usually I do a lot better on these, but I didn’t do much better than chance. I am severely out of practice, I guess. I also need to trust my instincts more.
15/20 male. I was looking at the eyes too, yet seemed to have got a lot poorer results than most other people that were looking at the eyes =\
Male, 19/20 … I missed the reserved one as well (Blondie ?).
But like others I’d read about the relevant research and was mostly just watching the eyes.
Did they all smile afterward? Was it fake or genuine? 
It’s kind of a shitty exercise though, isn’t it?
What were the subjects told to do? “OK, give me a genuine smile. Next.” “OK, give me a fake smile. Next.”
A bunch of “fake” smiles to me seemed friendly and honest enough. I put myself in the position of being introduced to these people and no alarm bells were going off with me thinking “Christ, this guy’s a sociopath and is going to knife me!”
Of course I might feel differently if I scored higher than 12! 
Yeah, I wondered the same thing. Seems the easiest thing to do would be to videotape people watching a humorous video or something, but the end of each smile seems to be at cue, as if someone was standing just off camera saying, “OK, got it. Stop smiling now, please,” which would totally inhibit my real smiles and get you a lot of self-conscious smiles, not truly genuine ones.
20/20, M. Pretty easy, on only a couple was I less than positive, and on those just going with my first instinct apparently worked. I had heard before that the key was in the eyes, however.
What it almost seemed like they did for some – and what they absolutely should have done for all – was to run the video in reverse when they wanted to bring the face back to baseline. A lot of the fake smiles were clearly “on, now off” types, which would be a dead giveaway – genuine smiles tend to linger. Or, they could have simply stopped the vids before each smile was wiped.
15/20 Male
Male 3/20 correct.
I’m not certain if something went wrong though, half the results were broken.
Female, 19/20. Missed #3.
I already knew the trick about the eyes, though.
14/20, female
(wrong answers evenly split between real and fake)
17/20, male.
11 of 20, Male. I was totally guessing on every one. How does the “administrator” of the test even know which ones are real?