An interesting study for sure - I'm PM you my email address if you're inclined to send the whole thing. But from what you've posted here it doesn't seem to refute the idea of separate punishment and rehabilitation. And from what you said:
Obviously, if you were in a prison environment which was harsh and demeaning, any subsequent rehabilitation program would have to undo the damage done during the 'punishment' process.
I would actually argue that trying to rehabilitate someone during punishment simply won't work for the very reason you described. You cannot punish someone and rehabilitate them at the same time. This might well be the reason that prison, as a correctional facility, fails so miserably. As you posted here:
Deprivation of liberty is a very serious punishment.
How could someone receiving "a very serious punishment," at the same time, be rehabilitated for society? We know this doesn't work. Rehabilitation would have to be a process of inclusion, and how could that be achieved in the confines of a prison, locked away from society?
The Stanfield Prison Experiment is also extremely flawed. If you actually check any of the criticisms, you'll realize that it cannot be, and was never intended to be generalized to a prison setting.
Check the aim of the study. It had NOTHING to do with corrections, or criminology. It was simply an experiment on social influence and de-individualization.
In an actual prison, the prisoners aren't actually middle-class college students. Furthermore, the people selected for the Stanfield Prison Experiment were intended to be psychologically healthy and well-adjusted individuals. Actual prisoners are anything but.
Yes, the Stamford Prison Experiment was flawed. Any experiment over time is always replaced by more modern studies and findings. Zimbardo stands by his work though, for good reason. The recent revelation of what happened at Abu Gharib sits very well with his findings amongst a varied base of prisoners in much harsher circumstances and wildly differing conditions.
As for having nothing to do with corrections or criminology, given the framework of prisoners and prison guards, it's clear that it was an experiment on social influence in a prison environment. It wasn't criminology by any stretch of the imagination tho.
The reason candidates for the Stamford Experiment were screened to be healthy, well adjusted individuals was to show the extremities in the effects of incarceration. And it did just that.
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I'm sure we can both agree that the correctional system, as it stands, needs changing simply because we know it's not working. It's not working as a deterrent, and it's not working as a rehabilitation process.
From that, we can look at the options that could possibly made to improve the situation.
And going back to the topic, I believe that a rehabilitation would have to be a process of inclusion, which would lend itself to giving the prisoners the right to vote.
Good luck in your exams.