I hope you're right also. But like I said before, an individuals opinions about what they would or would not do have been shown in empirical studies to have no predictive power regarding their actual behaviour when placed in particular types of situations.
I don't think I would have fallen for the McDonalds scam. I don't think I would have behaved so shockingly in the SPE. I don't think would have participated in the Nazi atrocities. I certainly don't think that you or any other individual Booktalk member has indicated that they are particularly likely to fall for any scam or participate in genocide, but then again, whatever qualities predispose a person toward these actions, they do not appear to be detectable through conversation.
Everyday I ignore countless emails from people promising me they can extend my penis size up to 18 inches or that if I just forward them my bank details, they'll send me millions.
Zimbardo does a good job of showing that the situation is important to determining behaviour, but that it is particularly important in novel situations and institutional settings. Now, most situations are not novel. They're familiar, and we have an internal script for how we should behave. We know what the norms are, but when we find ourselves in a situation where we do not know what the norms are or what is expected of us and the main sources of advice is an authority figure, we're liable to take his or her advice.
No, not all guards in every prison make the mistakes made in the SPE prison. But the variable does not seem to be the guard, but the prison. I don't have the book to hand, but the former correctional officer who abused the prisoners in Abu Gharib was a perfectly good guard when he was in the States.
Remember, the guys who went into the SPE were supposed to be normal. They were good kids randomly assigned to their roles. Yet, some of them acted in what you could call a heroic fashion while others became monsters. Had the dice rolled otherwise, the heroes might have been the monsters, or would at the very least, probably have collaborated with the monsters.
I would not argue that the individual's personality is not important to determining their behaviour, only that in particular types of situation, it is the situation that is most important and individuals, regardless of their self beliefs.
Even bad apples are good most of the time. The thief may treat his wife well. The murder may give money to charity. The pedophile may help old ladies across the street. But in certain situations, they act in an evil manner. If you can prevent these situations from arising, then the world becomes a little better.
I don't think that the SPE offers a miracle cure for everyday evil and I doubt that Zimbardo would argue as much, but it shows us that situations are powerful. One of the more important things the individual can do to avoid committing evil acts is to avoid situations that are known to lend themselves to evil actions.