So different groups have different definitions, and then they clash on those. So it takes adept leadership to say we're going to work through these.

What sort of difficulties would happen when people of different cultures try to come together to worship? Tiny little things such as let's tell jokes with each other.

So it may be a language that separates you - again, social networks. But second-generation Asian and Hispanics, second, and third and fourth and so on, they are much more likely to be in integrated churches than are blacks or whites.

Call-and-response style, yes, exactly. So whenever different groups get together then there has to be this long period of negotiation. How will we worship? What's acceptable? What's not? If I want to say "Amen" can I?

We've done a lot of studies to see when they do happen, why, and I mean there's a variety of reasons. But one, it starts with a commitment where they decide this is going to be who we are. Maybe it's out of their faith, a new way of looking at their faith, that we must be integrated across race.

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.

It's one of the things we find in these congregations is that they are much more likely to be sort of up-beat worship styles, more likely that people in these congregations say "Amen," maybe get up and dance some, tend to be a little bit more lively than a typical white service would be, but not as lively as a typical black service would be.