Mission teams, engineering teams, surgical teams, audit teams, judiciary panels, and advisory councils develop unspoken norms - group heuristics if you will – patterns of communication so deeply hidden that they are invisible even to those within the group.  These patterns become the lens through which the group makes all interpretations - the way it lives, breathes and learns. It controls how the group communicates, solves problems, and recognizes the environment - these patterns are the most powerful influence on group effectiveness.