Contagious laughter (when you start laughing after seeing someone else laughing) is a sign that you are extremely social and influenced by the emotional reactions of others. Explosive laughter usually occurs with someone tries desperately to suppress their laughter over time and eventually they just can’t hold it in any more. If you typically explode into a fit of giggles, you might be tightly wound and you try to hold your emotions in. Sometimes you laugh at yourself, showing self-confidence and sometimes you laugh at other people’s expense, which is slightly less flattering form of laughter.
