If you want to convince someone to do something, give a reason. This sounds obvious, but many people neglect to attach a “because” to their request. In famous experiments conducted by Harvard social scientist Ellen Langer, she approached people waiting to use a library copy machine and said, “Excuse me, I have five pages. May I use the Xerox machine?” Sixty percent said yes. When she changed her request with another group to, “Excuse me, I have five pages. May I use the Xerox machine, because I’m in a rush?” 94 percent said yes.