Procedure of Zimbardo's prison study
1. They were randomly issued one of two roles; guard or prisoner
2. Both prisoners and guards had to wear uniforms
3. Prisoners were only referred to by their assigned number
4. Guards were given props like handcuffs and sunglasses
5. No one was allowed to leave the simulated prison
6. Guards worked eight hour shifts, while the others remained on call
7. Prisoners were only allowed in the hallway which acted as their yard, and to the toilet
8. The guards were allowed to control such behaviour, in order to emphasise their complete power over the prisoners
9. No physical violence was permitted, in line with ethical guidelines and to prevent complete overruling