What I'm documenting can be hard to distill, because it's all around us like the air we breathe. I often need to go to a place where I can capture extreme moments.

You have these relationships with people that you care about, but I also try to stick to my job as filmmaker and be fair and truthful about what I saw and my experience of the people, hopefully informed by a deep understanding of them.

During the Reagan eighties, the idea that money was a good thing - it was good to be rich; that wealth was a reflection of your character. We see this today in perceptions of Donald Trump: the idea that money is an expression of success and even goodness. I compare that with my dad's generation, where the American Dream was about giving your kids a better life, but not just in material terms. The American Dream was also about doing something good in the world. The home was at the center of the dream, but home also represented community, shelter, and stability for your family.

Race is a huge factor when it comes to income and social inequality, and it plays a role in the structural barriers you are talking about. But when you're in the upper echelon of the 1 percent - even though it's certainly a more white demographic overall - there are fewer barriers.

I've often used the extremes in my work to comment on the mainstream. I think that sometimes a subject that I'm working on, like popular culture, is so present all around us that they're hard to see. It's like: How do you see the air you breathe? How do you see how it affects you?

The people in the popular group say there is no peer pressure because they are at the top of the food chain. Really what they are doing is just eating away at everybody else.

The 1970s were the height of social mobility. College was accessible. My grandfather was a poor immigrant who went to a public school in Ohio, and my father went to Harvard. That wasn't unusual. There was a feeling that anything was possible and you didn't have to be born into money to have a successful life. Now, people don't believe in the idea that anything is possible. We have more inequality than we've had ever before and a greater concentration of wealth in the hands of a few.