Sometimes, the word 'voluntary' is a little complicated.

The opening scene in A New Hope, when you see the huge ship, it goes on, and on, and on, and on, and on... that is like a joke of awesomeness.

So, you could often say things are terrible and that accounts for what happened, or things are really bright, and that accounts for what happened. Often, the real explanation for what happened is much more subtle and interesting and involves maybe small shocks or what a couple people did on a Wednesday morning that changed the arc of history.

It's very common to say that Star Wars in the late '70s, that was kind of perfect for Cold War culture and the aftermath of Vietnam in the '60s to have an upbeat, hopeful, cartoonish tale of a hero's journey. I think those explanations are easy to offer and almost always wrong.

Once we know that people are human and have some Homer Simpson in them, then there's a lot that can be done to manipulate them.

Donald Trump and Senator Cruz have occasional Manichean tendencies.

Groups become more extreme and entrenched in their beliefs and polarized from others when members only exchange information that reinforces their views and filter out all else or never learn of alternatives. Thus they narrow their options, and magnify each other's prejudices and misconceptions. This trend leads to blind spots in decision making and to extreme behavior, even terrorism.