Seen here:

Harvard psychologist and APS Fellow and Charter Member Ellen Langer observed similar rule-based behavior in a typical office setting. She had researchers ask if they could cut in line to use a copy machine. When they simply said, “Excuse me, may I use the copy machine?”, only 60 percent of the subjects complied. When the researchers gave a reason — “Excuse me, may I use the copy machine because I’m in a rush?” — 94 percent said yes. Langer tested this one more time with the phrase, “Excuse me, may I use the copy machine because I need to make some copies,” and again 93 percent of respondents agreed — despite the fact that “I need to make some copies” is not really a very good reason for cutting in line. The way Langer and Cialdini describe it, people hear the word “because” and assume that there is a good reason. That is to say, the word “because” is a shortcut people use to distinguish between good arguments and bad. "