Is our biology contributing to Church segregation?

Invisibilia is a podcast that explores the "invisible" forces that affect life. In a recent episode the reporters explore "The Power of Categories" and second half of the episode talks about a retirement community. 

If you don't want to take time to listen to the episode, or at least the second half, here is the setup. 

Man from India (Iggy) sets up a retirement community (Shantiniketan) that feels more like his native country. Other retiring people from India are attracted to  being a part of a community where they are no longer an outsider. While the community does not turn non-India people away it is still a community that can feel rather exclusive. The original founder does not want his children to live in a community like this - too insular - but he also feels that people are like salmon and as we get closer to death we desire to return back to what is most comfortable or familiar. And according to Jeff Greenburn, a psychology professor at the University of Arizona, humans get just a little bit more racist as we move closer to death. Here is the transcript from this point:

GREENBERG: I am a professor of psychology at the University of Arizona.

MILLER: And for the last 30 years, he's been studying how we behave when death is on the mind.

GREENBERG: That realization that, someday, we're not going to exist.

MILLER: And Iggy is absolutely right. If you raise the specter of death in a person's mind, which you can do experimentally, by the way, by simply asking a question like...

GREENBERG: ...What do you think happens to you as you physically die and once you're dead?

MILLER: People like people in their own group way better than they do when they're not thinking about death.

GREENBERG: So we had them rate them on, you know, traits like, you know, honesty, kindness, intelligence.

MILLER: Christians like Christians better. Italians like Italians better. And Germans, who most of the time are actually pretty lukewarm on other Germans...

GREENBERG: I think it's still - it's lingering, you know, guilt.

MILLER: ...If you get them to contemplate their own mortality, suddenly they really like Germans.

GREENBERG: So if you interview Germans near funeral home, they're much more nationalistic.


MILLER: But it's not just that we like our own more. Its reverse imprint is also true. We like people outside of our group much, much less.

GREENBERG: People become more negative toward other cultures.

MILLER: So why? Why might we do this?

GREENBERG: Well, because death haunts us as it does. We have to do something about it.

MILLER: Greenberg thinks it's this strange way that we try to fend off death. His thinking goes that people who are not like you, who do not share your language or your values or your beliefs, well, in some very primal way, it's like they can't see you.

GREENBERG: And so to manage the terror that we're just these transient creatures...

MILLER: ...We shoo those people who make us disappear away.


MILLER: That is, when you dive deep into your own category, what you're actually getting is the illusion...

GREENBERG: ...That we're significant and we're enduringly significant.

And so if it is true that human individuals become more concerned with surrounding themselves with their own when they are thinking about their own death, is is also true that human institutions become more concerned with surrounding themselves with their own when the institution is thinking about it's death? Does the chatter of the "death of the Church" and the Church's inability to draw in new Christians create a feedback loop where the Church is only able (or willing) to drawn in others who look/act/feel like us?