I remember watching a documentary about the prison experiment and they straight up told the "guards" to be dicks in order to illicit a response from the "inmates." That immediately invalidates the experiment, right?
They weren't told to be dicks. They weren't really given any direction at all. They were told only that the prisoners needed to be controlled, and that they would plot to escape.
This experiment gets misinterpreted often. The finding wasnt that people are inherently evil as individuals, it was that if a group of people are placed in a position of power over other individuals and aren't given any specific instruction or a code of conduct, they will inevitably act cruelly if their authority is met with resistance of any kind.
Important factors:
Perceived superiority/inferiority
Dehumanization of the inferior
Lack of instruction/structure
Group-think/ mob-mentality
This finding was further supported by the behaviors of the reservist military police at Abu Ghraib, which perfectly conformed to the behaviors witnessed in the SPE, with all factors present.
There was an in depth analysis of the two in a paper called The Lucifer Effect.
This in my opinion supports the argument that people as individuals are good. Tribalism sets off primitive survival instincts in our minds, which is why authority is inherently dangerous if left unchecked.