Testing out the "brief" exposure clause, are we? Lol. Good deal though.
I'll pass on commenting on the stereotype thing, it is what it is, and it does indeed exist for a reason-if none other than some folks going out of their way to live up to it..
The eye-contact thing. That alone can be plenty effective. A lesson I learned when I moved to NYC many yrs back. I noticed all the NY'ers had this aversion to eye-contact, and observed a lot of folk's reactions to "thugs" and hooligans on trains, the street etc..(politely translated as cowering candyasses..)
So, I adopted an opposite approach. Every single time I got onto a train or subway car, I went out of my way to make eye contact with every single person on that car-all the more so, the wannabe gangstas and "thugs". Even the most "bad ass" wannabe punk quickly departed the train at the next stop-every, single, time.