'13 Year Old Boys' aren't always just 13, the age it ranges from is about 12-16. It is infectious, therefor, be careful of who you surround yourself with.

Listen bands like Avenged Sevenfold, Slipknot, and Hollywood Undead
Most times, they drink Monster Energy Drinks, and save the cans.
They generally wear baggy pants, skull T-Shirts, and DC shoes.
They think they can BMX or skateboard, when usually they can't.
Whenever they go out, they travel with they're friends more than likely.
They often times like girls who wear T-Shirts with dinosaurs and dragons on them, wear lots of fake bracelets, and wear fake glasses.
Frequently, they like their mom better than their dad.
And last, but not least, when they take pictures of themselves, their hair is in the way of their face.

An age group actually really stupid, but their reputation is made worse by Encylopedia Dramatica.
In their article, it states that "13 year olds can also be from 10 to 18." Too bad ED is too stupid to realize that they are the ones 19+ writing articles on teenage boys...just saying. Oh, and this definition will cause a large amount of butthurt from EDers.