I assume based on... semi-logical thinking. "Teen" 12-18 (or so). If you are a teen, you are a kid.
TOGOT

Well, logically, we never grow up. Once people turn 18, they have a government title of a "adult" but, we don't ever become a adult mentally until about 35-40. I've done a social experiment on this.

"It's not safe to share your age online"
(1/2 of chess.com players have names on profile)
"But it is safe to share your name. Cause there are less 11 year olds than Charles Yangs."
Kids these days. Always so nosy.

"It's not safe to share your age online"
(1/2 of chess.com players have names on profile)
"But it is safe to share your name. Cause there are less 11 year olds than Charles Yangs."
Kids these days. Always so nosy.
Now you are getting too serious.

Yes, yes I am. Don't call me a kid ever again unless you'd like to see me put your horrible tomato in a pot to make a potion to kill your family....
Yay!