Self control not to do certain things to others, of course exists. That doesn't mean that everyone can act calm in any situation. Some people break easier than others. But just look at culture. I live in a very disciplined kind of culture where people simply DON'T SHOW EMOTION. I mean of course they don't have totally flat affect, but people from other countries find us cold and spooky. But I am pretty sure it rubs off on other behavior as well. Self discipline is a good thing. Me, I feel awkward in cultures with a lot of affect. Absolutely not safe the slightest.