Back in the day when university psychological experiments were not considered unethical, two very informative studies took place. One at Yale and one at Stanford, the latter was conducted using hungry and financially desperate college students; the Yale study used paid participants ($4.00 and 50¢ for transportation) recruited from the local New Haven area. Each experiment today would be considered highly unethical. But what the hell, no one then seemed to care much.
The Asch experiment is also part of the psychological mix. I have just read Asch’s Scientific American article from 1955, and it is distressingly applicable to the Convid psyop.
About "This criticism included Zimbardo’s own participation in the experiment, essentially guiding the participants to behave in certain ways to guarantee the outcome Zimbardo was looking for" -- I am not sure that this criticism is fair. First, I am not sure that Zimbardo had a clear idea of the outcome. True, now we know the fundamental attribution error, attributing to character rather than circumstances, and want to avoid it, but back then this idea was newer and more surprising. Second, Zimbardo seemed to be trapped in the circumstances himself, rather than guiding it so explicitly.
I say so based on taking Zimbardo's "Psychology of mind control" course in its final offering (1989). Even though I was a physics major, now teach physics and math, and write textbooks, that course has been by far the most valuable course for my daily life, particularly in these years of Convid tyranny.
Here's what's in my memory from 32 years ago. I think that the following details are correct, but it was a long time ago.
In the unit on the prison experiment, Zimbardo described his role in the experiment and how it got out of hand. He was the principal investigator (PI) and, in what he described as a serious mistake, also played the prison warden. As word of the abusive conditions got out, parents came to him as PI, concerned about their sons. He, by his own description, forgot his role as PI and played up the prison warden, even turning deliberately to the father to say, "You don't think Johnny can handle it?" to play on the machismo. The father would then say, "Oh, he can. Come on, honey, we're going." These psychological moves helped keep the show running.
Although the experiment was scheduled to last 2 weeks, the abuse was getting so far out of hand after only 6 days that the graduate students started coming to Zimbardo in distress. One student, Christina Maslach, was particularly distressed and convinced him to end it. Zimbardo noted how struck he was by her action and mentioned that she became his wife.