Brainstorm a bunch of actions and outcomes. Each member privately assigns an utility to each possible outcome, how likely they think each action is to lead to each outcome, how trustworthy they think each other member is on the question, etc. etc. Then you feed all of this into a black box AI algorithm and it outputs what action should be taken, which everyone simply has to take on faith until they have enough examples to take it on induction.

So my answer is the meta one of "I don't know, but whatever it is it'll be a complex or even downright inelegant, found through testing and interaction with the real world and/or simulations rather than armchair theorising or mathematical derivation from first principles, probably involve large datasets and some kind of machine learning algorithms, and not possible to implement well on a human brain".