The Rule of 150

…we have to keep groups below the 150 Tipping Point.  Above that point, there begin to be structural impediments to the ability of the group to agree and act with one voice.  If we want to, say, develop schools in disadvantaged communities that can successfully counteract the poisonous atmosphere of their surrounding neighborhoods, this tells us that we’re probably better off building lots of little schools than one or two big ones.  The Rule of 150 says that congregants of a rapidly expanding church, or the members of a social club, or anyone in a group activity banking on the epidemic spread of shared ideals needs to be particularly cognizant of the perils of bigness.

Malcolm Gladwell, The Tipping Point: How Little Things Can Make a Big Difference