This quiz from a few years ago has been making the rounds. In a nutshell, take a look at these cropped faces, try to identify the emotion shown. It’s all multiple choice, 36 in all, goes pretty quickly.
I generally found that if a particular face brought up an instinct, that first instinct was the correct answer. Enjoy.
UPDATE: Not sure why, but it appears the quiz comes up fine on the Mac, but not on my iPhone. If you get a broken link on your phone, try it on your computer.