Even when a social situation calls for an emotional reaction, you should still remain equanimous. In fact, it’s in the moments where everyone else is the opposite of even-tempered that you should take the calmest approach possible and act in stark contrast to those who surround you.
This usually comes up when you’re watching some sort of spectacle with others that often demands reactions from you as a member of the crowd. Maybe the better solution is to avoid displays entirely and not to put yourself in these situations at all, but if you so happen to end up in one, remember that you still have no license to lose control of your mind and act at the whims of the game you’re watching. All spectacles of the sort are games—debates, news shows, sporting events—and hold little to no bearing on your life. React accordingly. More precisely, don’t react.