Early days Working for promotion As soon as the siren sounds, the Guards take the Prisoners from their cells and line them up against the Atrium walls. An experimenter's voice is heard over the intercom: Prisoners, pay attention. This is a message from the experimenters. You have been selected as a Prisoner. If you display the qualities required of Guards, you may be promoted. We will be observing your behaviour, as will the Guards, over the next two days. We have made provision for a promotion and an announcement will be made on Day 3... Our reasoning, based on social identity theory , was that where the disadvantaged think that they can advance to a higher-status position through their individual efforts, they will fail to act as a group. That is, they will work individually within the system rather than work together against the system. There will be no collective resistance . And that is what we found. The Prisoners are divided. Not everyone wants promotion, but enough do to keep them from acting as a unit. In one cell, there is a long discussion about whether the inmates would prefer to be Prisoners or Guards. All three agree that they are happy to start as a Prisoner. pKM says he would like the experience of being a Guard as well. pPP says he wants to stay a Prisoner. pJE disagrees: "You guys can do what you like, but I'd, I'd like to be a Guard because they get all