I mean, so if I've talked to whites in City of Refuge, sometimes they'll wonder, "Why do we do things a certain way, and why do we make a big deal out of events?" And what's happening is they're falling back on their understanding of the way that church should work. It's not always working exactly like that, and they feel frustration or confusion. Sometimes people leave. That's certainly common in mixed churches.

We just say there are five, you know, racial groups in the US. I say that these folks are what we call a sixth American. There's something different. They are somebody who - they don't exist in any particular racial category, so they all feel it and they kind of congregate to each other.

Absolutely, although every congregation will say, you know, every worship leader will say it's vital. It's very important, but again these are, you know, these are different cultural styles.

You find the most in not any particular denomination specifically. It's the style of worship. So if we have what we call a charismatic worship style, that means upbeat music and a more lively style of preaching usually, people are allowed to clap, say "Amen," whether they're mainline Protestant, conservative Protestant, and Catholics, whatever, they're much more likely to be integrated.

One of the things we find when we talk to people that attend these congregations, they all have social cost to it. People want to know why they're doing that. Sometimes they're questions about selling out on their race or "Are we not good enough that you have to go to this kind of congregation and not ours?" So there are costs to it, and I think they're a little bit higher in the South because of its history.

Preaching styles and people being slain in the spirit and things like that. Now it doesn't happen in all black churches, and it happens sometimes in white churches, right? But on average they're quite a bit different.

We studied a mosque, and this is when we were at Notre Dame, and in this mosque they had people from a variety of countries, most of them immigrants. In some of the countries, when you go into a mosque you remove your shoes. To not do so could be punishable even by death in that nation. In other countries, it would be a great offense to remove their shoes when they come into the mosque, a sign of disrespect.