Sometimes interviewer may ask you questions to understand little bit more about your personality and character. This can also aim to see more about your employment history.
Most job seekers find it easy to say "I never get angry" but isn't this unrealistic? Everybody gets angry for for reasons and not all type of angers are harmful. Sometimes you anger can mean that you are passionate about something and you can't wait to achieve. In this case you will have to explain how you can use this