I'm in the middle of a reverie right now so this may all be bullshit. I'd credit it to being drunk, but I've only had two glasses of chardonnay so I don't think I can get off that easily. I do wish desperately, though, that I could have found a liquor store somewhere within walking distance of my hotel.
In any event, I had a revelation while eating pizza and drinking wine at a little joint here in Bloomington. I started thinking about this tight loose distinction and when it might be adaptive to be a loose group. As I've done so many times before, I started racking my brain about what sorts of environmental conditions might be conducive to looseness and I even came up with a couple of scenarios. For instance, it occurred to me that it might be advantageous to be a loose group if you experienced a loss of membership through mass emigration. This would allow you, at least in the short term, to reach out to new people to become members of your group. However, this seemed at best to be a short term strategy. I also wondered about colonization of a new habitat by multiple groups that, individually, were too small to recruit many resources so that it would be advantageous to join forces.
All of that may pan out, but it's ultimately focusing on the wrong parameters. Completely! I can't believe that I've been so stupid.
Yes, environmental conditions are important, but they're a distraction. The real target we should have been pursuing all along is the conflict between group and individual level selection. As we know, group level selection can only take place when between group selection is greater than individual level selection. This is the story we're all familiar with. What we've missed, however, is the relative strengths of these two levels of selection. And therein lies the key! If group level selection is only slightly greater than individual selection, that that should favor tight groups. That's simply because individuals, though under less selective pressure than the group, are still under significant selective pressure. This accounts for why fundamentalism and existential security are so tightly linked. People living at the margins can do better when they belong to a group, but their security also depends very much on their individual adaptations. This is not the case, however, when group level selection is very much greater than individual level selection. Under those circumstances, what happens at the individual level becomes insignificant. The individual can display all sorts of variation because the individual is under very little selection pressure. This accounts for why existential security is so often associated with more "liberal" or loose churches. People belonging to those congregations aren't under tremendous selection pressure because they're living quite comfortably as they are.
And that, in a nutshell, is it! The rest is just commentary. Or so it seems to me in my current state.