Simplify the following text for a Grade 11 native English-speaking person.
Original: The Stanford prison experiment was a study of the psychological effects of becoming a prisoner or prison guard . The experiment was conducted from August 14th to 20th , 1971 by a team of researchers led by Psychology professor Philip Zimbardo at Stanford University .
Simplified: The Stanford Prinson Experiment was a scientific experiment done at Stanford university in 1971 .