I've finished Blueprint: The Evolutionary Origins of a Good Society, Nicholas A. Christakis.

From a review:

Christakis identifies the “social suite” as “the core of all societies.” These are eight capacities built into societies because they are built into every functioning human:

        The capacity to have and recognize individual identity
        Love for partners and offspring
        Friendship
        Social networks
        Cooperation
        Preference for one’s own group (“in-group bias”)
        Mild hierarchy (relative egalitarianism)
        Social learning and teaching

BTW, He writes that it takes both nature and nurture. IMO, a group that lacks one or more of these manifestations, is either no society or is metaphorically diseased.

Anyway, I'm posting this because it strikes me that these are characteristics of a successful adventuring party and ingredients for a successful RPoL.

P.S. And who is my in-group?

I'm listening to that audiobook at the moment, so in a sense, I'm your in-group.

In a broader sense, everyone on the site is. Within the site, I suppose the people who like the types of games and systems that you like would be your in group.