Control can be gained by finding a common bond between you and another person and exploiting it. It can be a common enemy or a common interest. Hitler, Mussilini, and Manson used common bonds to bring people together and raise them up against a common enemy.
Captain Kirk also used this control to lure officers down to the planet surface with Spock and Dr. McCoy. The officer should have realized that only Kirk, Spock, and McCoy ever return from these missions. He or she should have said forget you I'm not going to die today! But the control Kirk had made them forget about death.