In the comments to my post about family values and kin selection I made the comment that, as Christians, we try to extend family affection to all people.

Let's call this the storge-to-xenia shift (SXS).

The point I was trying to make in the Family Values post is that although family is a great and joyous good (when functioning properly) it is not a moral demonstration. Jesus explicitly makes this point in the Sermon on the Mount. Thus, what the world is waiting to see from the Christian community is the SXS. In making the SXS, the church is truly making a moral demonstration.

One way to make the SXS is to leverage the psychology of kin selection (the source of storge) to the purposes of xenia. This psychological leveraging is the proposal of the ethicist Peter Singer. Singer calls this notion The Moral Circle.

Singer suggests that human moral psychology is the height of simplicity, a simple two-step process. The first step is a simple identification algorithm which sorts kin from non-kin. Recall my post on the Magic Moral Number 150? The identification algorithm is a quick appraisal telling me if you, the person standing in front of me, is INSIDE or OUTSIDE my friendship/family group. Basically, it tells me if you are a stranger.

The second step of the moral system is to extend kindness toward friends/family. This happens naturally and instinctively in most cases. I don't really choose to treat my friends and family kindly. I just do. Once identified as part of "my group" affection flows easily and naturally.

But if you are identified as a stranger you fall outside of my moral concerns. I don't treat you with kindness. Rather, I treat you instrumentally, as a tool to accomplish my purposes in the world. And if you are not helping me accomplish my purposes I can dismiss you or remove you from my path.

There it is, in all its crystalline simplicity, the human moral system. To recap:

The Human Moral System
Part 1: Identification Algorithm
Are you friend/family or stranger?

Part 2: Response Algorithm
If you are friend, I extend familial kindness.
If you are stranger, I treat you instrumentally.

When you look at the outcome of this system, as Singer notes, you create a Moral Circle. Specifically, people inside your moral circle are at the center of your moral concerns. You treat these people as, well, humans. However, if you are outside my moral circle--you are stranger--you are not the focus of my moral concerns or efforts. You are a little less human to me, an infrahuman.

In the language of Kant's Categorical Imperative we can state that:

Inside my Moral Circle: You are treated as an end in itself.
Outside my Moral Circle: You are treated as a means to an end.

Obviously, the psychology of the moral circle is driven by kin selection. That is, narrowing our earthly concerns to the FEW makes good adaptive sense (and this is why family isn't a moral demonstration).

So, how can we make the SXS with this particular moral psychology in place? As Singer suggests, we work to EXPAND the Moral Circle. We do this my modifying the identification algorithm to label more and more people as "family." As we do this everyone becomes brother or sister to me. I begin to live in a world with fewer and fewer strangers.

What is amazing about this is how Singer's notion is clearly anticipated by the bible. The NT ethical vision is to live in a world without strangers. And this is accomplished by harnessing family metaphors and imagery and applying each more and more inclusively. As I've written before:

Thus, we see co-opted kinship language sprinkled throughout church. We call the church the "family of God." We call each other "brother" and "sister." Jesus is our “older brother.” God is our “father.” And the center of Christian worship is eating around a table, a symbol of home and family gatherings.

And who gets this “family treatment”? Jesus was asked this very question. The Torah expert asked Jesus, Who is my neighbor? It was a question about the Moral Circle. Where can I draw that line? Who is inside and who is outside? Who is family? And Jesus tells the story at the heart of his ethical vision: The parable of the Good Samaritan. Who is my neighbor? Who is inside my Moral Circle? Everyone. Everyone is now family.

Thus the gospel takes a moral psychology that is naturally parochial and small-minded and gradually universalizes it, allowing familial affection to flow toward all. As a psychologist at church, as I witness this expansion of kinship language, watching how it exploits our natural biases for good, I’m always amazed by the genius of it all.