(images courtesy the Stanford Prison Experment slideshow)
In 1971, a group of social psychologists including Philip Zimbardo and Craig Haney embarked upon a creative, groundbreaking experiment, which would be cited and referred to for years to come. They hoped to study the psychological effects of imprisonment.
For that purpose, they converted the Stanford Psychology Department's basement into a prison, complete with cells, and monitored by cameras. They recruited male college students, who completed a battery of personality tests, and randomly assigned them to two groups: guards and inmates. At the beginning of the study, there were no detectable personality differences between the participants in each group.
The "guards" (depicted in the bottom image) were instructed to maintain discipline in any way they saw fit, excluding physical violence. The "inmates" went home, and later were "arrested" at home with a police car, brought to a police station, and placed in prison after having undergone a series of booking procedures, which included being assigned a number and special clothes (depicted in the top image). Zimbardo assigned himself the rank of warden, set the guards loose on the prisoners, and the experiment was to run for two weeks.
The research team had to stop the experiment after six days.
The details of what happened are absolutely fascinating, and I strongly recommend following them in this slideshow, or watching the excellent documentary Quiet Rage, which contains footage from the experiment. But the bottom line was that, once in role, both guards and inmates quickly socialized into their roles, and the research team feared the ramifications of the guards' increasing cruelty and the inmates' psychological situation. Despite the fact that the guard and inmate groups were psychologically indistinguishable from each other at the beginning of the experiment, as days went by participants strongly socialized into their roles.
Erving Goffman, who studied roles and status, was a big influence on the Stanford experiment team, as well as on labeling theorists. One of his best-known books, Asylums: Essays on the Social Situation of Mental Patients and Other Inmates, examined how people are socialized into their roles as inmates in enclosed social settings that he named "total institutions". A total institution is a place in which all aspects of life are governed by the institution, there is a strong hierarchy, impermeable boundaries between the inmates and the staff, and your status as an inmate becomes the central aspect of your life. Prisons are an excellent example.
During the 1960s and 1970s, prison researchers found that the entrance rituals into prison, as well as the experience itself, makes inmates strongly identify with their inmate identity. In other words, being an inmate becomes one's "master status", overshadowing other roles and identities that the person has, such as being a father, a friend, an employee, etc. One of the main obstacles to reentry after release from prison is the persistent stigma generated by this master status. The challenge of this status lies not only in how others perceive you, but also, as the Stanford experiment teaches us, in how you perceive yourself.
These days, my colleague Lior Gideon and I are conducting a survey of Californians regarding their opinions about redeemability of formerly incarcerated people, and the extent to which they believe in rehabilitation. While the results might reflect a variety of considerations, such as cost, political opinion, fear of crime, and demographic factors, they might also reflect the public perception--shared by the inmates themselves--that "once an inmate, always an inmate". One of the important things to take into account when planning re-entry programs is finding creative ways to shed this stigma, persistent as it is, and move on.