The 4th social trigger is Familiarity. As a group there needs to be enough in common to create a shared language, knowledge base and communication style. A group that can function sometimes on unspoken understandings.
Operating from the same play book, acting quickly without the need for lengthy explanations and detail. Trust rules. Allowing and accepting, knowing each other enough to get on with it.
Keep the social distance otherwise you won’t be able to see the wood for the trees. Close, yet far away. On the same page, but bold enough to be the author of your own story.