If all women had to do 99.99% of the time to scare away dangerous men was stand up tall, puff our their chests, and yell loudly, I doubt we would be having this conversation.
Not a joke, actually. By and large, predatory men prey upon weak women. Women who are afraid of conflict, afraid of drawing attention to themselves. Gavin DeBecker, author of The Gift of Fear, wrote that one of the greatest things you can do in the case of being attacked is to very loudly and boldly reject their advances. "I TOLD YOU NO, LEAVE ME ALONE." The vast majority will run away because they can't be stealthy.