Principle 6: Social Bridges
The social nature of humans is another primary contributor to the success of our species. The reason we have large brains is to support that social requirement.
We work together within social groups or tribes through shared interests, those interests becoming our social "glue". One of the functions of the leader within a tribe is to keep that social glue strong, checking for weak points and re-inforcing as necessary. The leader therefore is the "social" leader with greater social powers, and through this they also become social "bridges" developing and creating networks linking tribes together. As leaders link together through their bridges, so they create tribal networks - communities of a tribal collective.