Emos are a group of people who have a certain pain in their life. Whether it be from family, society, whatever the reason. Because of this pain, emos have trouble fitting in, except in their own group of people who accept eachother for just being different. Emo literally is a lifestyle based on music. Listen to your music and act how you feel. It's not for everyone. Emos generally are very sad and act depressed, but be careful. Not everyone who is depressed is necessarily emo, you can be a happy person but still be emo. Of course, you will be judged highly if you are a happy emo.
There are all types of emos, from closet ones to vampires, and because of the diversity, there is no real behavior of emos. They are all different. Not whiny, not crying, not all are cutters. Cutters are people who have so much pain that the only way to let it out is to cut their own skin.
People who are stereotypical just don't understand.