Language is a tool made of many parts, and one of the most powerful parts is a single word that will get people to comply to your wishes. That word? Because. 

According to Harvard psychologist Ellen Langer, just using the word "because" increases compliance rates by 33 percent. 

Langer experimented by waiting in line for a copy machine and used two different phrases to see which one would help her cut in line faster. She said, "Excuse me, I have five pages. May I use the Xerox machine?," which resulted in a 60 percent compliance rate. In the second experiment, she said, "Excuse me, I have five pages. May I use the Xerox machine because I’m in a rush?" The compliance rate for that phrase was 94 percent. 

To determine if the helpful word wasn't "rush," Langer did one more experiment, using a different phrase: "Excuse me, I have five pages. May I use the Xerox machine because I have to make some copies?"

The compliance rate for that phrase was 93 percent. 

As you can see, a valid reason is not always needed. The word "because" is enough to sway others to your requests. 

(h/t Cognizance Magazine)