For teens! Why do we give each other stare downs when we walk by each other?

Insecurity.

We are raised to compete. At school to beat everyone else, get the better grades. In sports to win at any cost. In work to beat your colleagues to a promotion. In life, to beat rivals to our spouses. To get a better car than the Jones's next door. To send little Jimmy to the best school.

In a culture of competitiveness and non-cooperation, its hardly surprising teens stare down

I don't stare people down with a dirty look usually but it's just curiosity, as we are all young we like to learn things, even if you hate school you are just easily interested in things with people going on around you. And because we're young (as a guy) I look at girls to see if they're looking at me. Haha.

I don't think we always mean to look mean but sometimes we do.

I know right. I try not to look at other teenagers that I pass because it's polite to mind your own business rather than make eye contact deliberately with someone you've never met.

haha chyeah, know the feeling. Im 16 and when i walk past another girl my age or close to i compare them to me. Or check them out to see if their a *****.

Its just a thing, it passes.