The MythBusters test the myth that talking to plants makes them grow better. They set up several test groups of bush peas, and all are under the same conditions except the type of sound to which they are exposed.
The Stanley Milgrim experiment is a series of radical experiments that test the willingness of individuals to obey authority. Individual variables are changed in order to determine what influences the test subjects. In nearly every case, the fundamental result is the same.