2014-01-12 – A favorite idea, at least in the popular press, is that kin selection tends to make us cooperate more with close family members and compete more with those unrelated or distantly related to us. This supposedly accounts for moral codes that tell us to love our neighbors but to erase distant tribes from the face of the earth.

The idea has a lot of appeal. If you help your brother survive, a bunch of your genes survive with him. If you kill an alien, no big deal. You’ve enhanced your own survival by removing the threat. Of course, it works both ways. I don’t know the statistics on this, so I don’t know how likely it is that this view is true. I do know that slaughtering distant enemies is a part of human behavior.

But slaughtering close enemies is another well establish human pastime. So let’s look at the other side of the argument.

Who is your main competitor in life? Your brother or some poor slob on the other side of the world? In the vast majority of cases, your biggest competitor is your brother. Or your sister. So where’s the evolutionary “pressure” that supports kin selection?

Cain kills Abel. And before you know it you’ve got civil war. Tiny differences become deadly flash points.

When I was in college, I became friends with a Serbian guy and, through him, I met some folks who were writers in the Serbian émigré community in Chicago. One of the writers, upon learning I am a Jew, told me this extraordinary thing (in broken English): “Jew – Serb, no difference. But Croat – Serb, big difference.”

Now the first part of this statement was a nice gesture from my new Serbian friend to me. But the second part had me totally mystified. Serbs and Croats live in the same part of the world and they speak a language that outsiders (at least) call Serbo-Croatian. Furthermore, to me as a Jew, both Serbs and Croats are Christians.

Little did I know at the time, but these two groups work overtime to magnify the small differences between themselves. One language becomes two when one is written using the Latin alphabet and one is written using the Cyrillic alphabet. One religion becomes two when one is Orthodox and one is Catholic. Who knew? Of course, many years after my friend told me that Serbs were closer to Jews than Croats, that region of the world exploded with war and ethnic cleansing.

We’ve seen it time and again.

And so I have to ask: what makes one brother turn against another.