In Haney et al.'s study, how were the 'prisoners' processed upon arrival at the mock prison?

In Haney et al.'s study, when the 'prisoners' arrived at the mock prison, they were 'arrested' by actual police. This procedure was designed to enhance the realism of the mock prison environment. By using real police officers to carry out the arrests, the researchers aimed to create a more immersive and authentic experience for the participants, which would allow for a more in-depth examination of the psychological effects of being in a prison setting. This technique helped establish the authority of the guards and the powerless state of the prisoners, key elements that contributed to the overall dynamics of the study.

The other options do not accurately represent the procedures followed upon arrival. While introductions to guards and rules were part of the experience, they did not happen in the same immediate manner as the 'arrest.' Psychological evaluations were not conducted as part of the processing; the focus was on the prison experience itself rather than on assessing psychological states prior to the simulation. Filling out consent forms is a standard procedure in research but does not specifically convey the unique and impactful experience that characterized the arrival process in this study.