What if, despite your character’s best efforts, he or she responded to bad news with an outright tantrum? Write a scene in which your character receives bad news and watch what happens as he or she struggles with his or her tantrum tendency. Will it come out? Will it subside? Is he or she even aware he or she is acting like a three-year-old in the corporate board room? And how do others respond, based on whether they know him or her really well or not?
Give this exercise fifteen minutes of your time. Write it up and see what happens.