The Stanford prison experiment (SPE), was held at Stanford University in August 1971, by a research group led by psychology professor Philip Zimbardo. The experiment engaged 24 college students, equally divided in the roles of "prisoners" and "guards" and each paid $15 per day (Approximately $90 in 2017) to participate in a 7-14 day period of stay in a prison-alike environment, settled purposely in the basement of the Stanford's psychology building.

The guards' suit was stereotypical of a certain common perception. They were dressed with uniforms and mirror sunglasses, carrying a whistle around their neck and even a billy club. They were also specifically instructed by Zimbardo, who held the role of "superintendent", a sort of prison's director, as follows:

You can create in the prisoners feelings of boredom, a sense of fear to some degree, you can create a notion of arbitrariness that their life is totally controlled by us, by the system, you, me, and they'll have no privacy ... We're going to take away their individuality in various ways. In general what all this leads to is a sense of powerlessness. That is, in this situation, we'll have all the power and they'll have none.

After answering to a local newspaper and expressing their intention to participate in a vaguely described study on the psychological effects of prison life, the applicants whose been assigned with the prisoner's role were "arrested" at their homes by real city police collaborating with Zimbardo, blindfolded and taken to the simulated prison environment.

This is the description of the prisoner's introductory modalities to the experiment:

A degradation procedure was designed in part to humiliate prisoners and in part to be sure they weren't bringing in any germs to contaminate our jail. This procedure was similar to the scenes captured by Danny Lyons in these Texas prison photos.
The prisoner was then issued a uniform. The main part of this uniform was a dress, or smock, which each prisoner wore at all times with no underclothes. On the smock, in front and in back, was his prison ID number. On each prisoner's right ankle was a heavy chain, bolted on and worn at all times. Rubber sandals were the footwear, and each prisoner covered his hair with a stocking cap made from a woman's nylon stocking.

The experiment, whose details you can read here, narrates of an escalation of abuses and real tortures perpetrated by the guards to the prisoners. It was forced to be aborted after seven days from its beginning, due to the strong ethical and moral objections of Christina Maslach, a psychology student that was invited to observe the experiment and the future wife of Zimbardo.
Slowly during the experiment, the applicants lost their perception of individuals and fully embraced their role. This was applicable for Zimbardo too, who had to admit he had been "grossly absorbed", allowing psychological and physical violence to be performed under his supervision.
One third of the guards showed "genuine sadistic tendencies", and the prisoners have reported severe psychological traumas.

A clear demonstration of the depersonalization and deindividuation process, is given by the story of prisoner #819 (obviously, prisoners were called by their number and not with their name):

The only prisoner who did not want to speak to the priest was Prisoner #819, who was feeling sick, had refused to eat, and wanted to see a doctor rather than a priest. Eventually he was persuaded to come out of his cell and talk to the priest and superintendent so we could see what kind of a doctor he needed. While talking to us, he broke down and began to cry hysterically, just as had the other two boys we released earlier. I took the chain off his foot, the cap off his head, and told him to go and rest in a room that was adjacent to the prison yard. I said that I would get him some food and then take him to see a doctor.

While I was doing this, one of the guards lined up the other prisoners and had them chant aloud: "Prisoner #819 is a bad prisoner. Because of what Prisoner #819 did, my cell is a mess, Mr. Correctional Officer." They shouted this statement in unison a dozen times.
As soon as I realized that #819 could hear the chanting, I raced back to the room where I had left him, and what I found was a boy sobbing uncontrollably while in the background his fellow prisoners were yelling that he was a bad prisoner. No longer was the chanting disorganized and full of fun, as it had been on the first day. Now it was marked by utter conformity and compliance, as if a single voice was saying, "#819 is bad."

I suggested we leave, but he refused. Through his tears, he said he could not leave because the others had labelled him a bad prisoner. Even though he was feeling sick, he wanted to go back and prove he was not a bad prisoner.

At that point I said, "Listen, you are not #819. You are [his name], and my name is Dr. Zimbardo. I am a psychologist, not a prison superintendent, and this is not a real prison. This is just an experiment, and those are students, not prisoners, just like you. Let's go."

He stopped crying suddenly, looked up at me like a small child awakened from a nightmare, and replied, "Okay, let's go."

Notwithstanding its importance, this experiment came under heavy criticism and could never be repeated nowadays, due to stricter ethical protocols.

The Third Wave

Source: "Die Welle" (movie, 2008)

"How is it possible that a whole nation blindly followed such an evil dictatorship, denying its horrible crimes?"

Let's go back to Hanna Arendt for a moment. When thinking about the atrocities of the Nazi regime during the second world war, it's possible that we came to wonder and ask ourselves a similar question.
Perhaps, another thought crossing our mind could have been something like: "I would have been different, I would have joined the resistance, I would have never accepted such crimes against humanity without questioning".

Indeed we are different, better, more prepared. Aren't we?

In 1967, Ron Jones, a high school history teacher, set an enlightening experiment with his unaware students, an experiment that they would have never forgotten.
It took place at Cubberley High School in Palo Alto, California, and aimed to give an answer to the incapability of the students to figure how German population could have claimed their ignorance about the Holocaust.

Ron Jones decided that the best answer was a demonstration through a social experiment: he created a movement, named "The Third Wave", similar to an exclusive club within the High School. The purpose of the movement was to eliminate democracy and its motto was "Strength through discipline, strength through community, strength through action, strength through pride".

Similarly to the Stanford Prison's one, this experiment soon started to show increasingly worrisome behaviours between the students and soon started to derail and get out of control. To give an idea of the almost contagious spreading of the experiment between the students, hereunder I reported an abstract taken from teacher Ron Jones' original short story, first published in 1976:

Monday - day 1

In speed drills the class learned to move from standing position to attention sitting in fifteen seconds. In focus drills I concentrated attention on the feet being parallel and flat, ankles locked, knees bent at ninety degree angles, hands flat and crossed against the back, spine straight, chin down, head forward. We did noise drills in which talking was allowed only to be shown as a detraction. Following minutes of progressive drill assignments, the class could move from standing positions outside the room to attention sitting positions at their desks without making a sound. The maneuver took five seconds.
It was strange how quickly the students took to this uniform code of behaviour I began to wonder just how far they could be pushed. Was this display of obedience a momentary game we were all playing, or was it something else. Was the desire for discipline and uniformity a natural need? A societal instinct we hide within our franchise restaurants and T.V. programming.

Thursday - last day of the experiment:

On Thursday I began to draw the experiment to a conclusion. I was exhausted and worried. Many students were over the line. The Third Wave had become the centre of their existence. I was in pretty bad shape myself. I was now acting instinctively as a dictator. Oh, I was benevolent. And I daily argued to myself on the benefits of the learning experience. By this, the fourth day of the experiment I was beginning to lose my own arguments. As I spent more time playing the role I had less time to remember its rational origins and purpose. I found myself sliding into the role even when it wasn't necessary.

The experiment lasted 4 days, even less than Zimbardo's one and was interrupted in order to avoid serious consequences. Note that, similarly to Zimbardo, who ended up being deeply influenced by his own experiment, also teacher Ron Jones admitted in his report the fascination of his position of power and predominance over the students.

Conclusion

There's a common thread that links Arendt's essay and the two socio-psychological experiments above described: the vulnerability of the individual oppressed or simply engulfed by an authoritarian control system and the speed of the social depersonalisation process, triggered by specific environmental circumstances. At the same time, the two experiments and, in particular, Eichmann's hearings, evidence the presence of a foreseeable pattern in human behaviour, represented by a wish for conformity with the mass. This is particularly evident in the process that led a whole nation - with some relevant exceptions, tough - to blindly abide and feed the well lubed Nazi dictatorship. Such desire emerges inexorably when the individual is forced or, in general, surrounded by an authoritarian and well organised superstructure, whether this is a prison, a movement, a political party or a bureaucratic apparatus.

Perhaps, sometimes it's worth to invest more time in understanding our human nature, our innate brain mechanisms and social dynamics and, most of all, try to learn from History.
We may raise our antibodies and counter our instincts, but this requires a preliminary effort of knowledge and self-awareness. Only this way, through exercising our criticism, we will be able to recognise the next Leviathan who's going to menace our freedom.

I will end with a question: at what level can we discern some of the above mentioned social behaviors within the Steemit platform?