Important finding - the minorities did better, but only because they were unlikely to trust that their society was just and would help them.
They think that society discriminates against them, the more you think cops aren't trustworthy, the more you are likely to stand up for others when you see something you don't approve of.
Heroic people are those who distrust the existing system.
So a White Nationalist would be hero material, because they feel like they are representing a race that is persecuted by the system they exist in.
According to this video, this is the exact catalyst for stepping out of line to provide aid to someone in need, so they'd do it (especially if it's a White person they'd be helping).
Anyone who feels like the system hates them would be willing to go out of their way to help someone in need, you don't have to actually be an oppressed minority, you just need to feel like one.
Heck, merely being openly racist is doing something that fits the zimbardo definition of heroism, acting selflessly, based on what you think is right, at great personal risk or cost, even in the face of the apathy or outright disapproval of those around them.
But doesn't this have a dark side?
What about someone like this who encounters a situation where they intervene and it results in a negative result, because they've gotten involved in things without having all the information?
They could end up contributing to a problem by thinking they are acting like a hero, they might even unwittingly become the allies of a villain, or the thing that actually kills the person they tried to rescue.
Are you saving as kid from a kidnapper? or just beating up a father dealing with his bratty kid's tantrum?
Are you helping someone whose been pierced by a foreign object? or are you causing undue damage and bleeding, ultimately killing the person you are attempting to save?
There was that true crime video where a man kills a girl's father to help her escape from the physical and sexual abuse she says she experienced from him, but in reality she just wanted him dead.
Furthermore, heroism could go one way or another, as these types of people are able to be recruited into a cause easily, and it could be a cause to make things better, or one to make things worse, while seeming to it's members as a way to make them better.
Heroism lacks a moral dimension, and it lacks a dimension of being someone who makes things better, all it takes to be a hero is to fit the zimbardo definition, which is concerned with what the hero thinks is right.
If you kill someone or commit an act of domestic terrorism, you could be a hero by this definition, you are taking a huge personal and moral risk, for the sake of something you believe to be right, at great personal risk or cost, where most people are apathetic or outright opposed to taking such action.
There doesn't seem to be anything here yet