The end of neighbours
How our increasingly closed-off lives are poisoning our politics and endangering our health
Brian Bethune
In the 1990s, Oxford primatologist and evolutionary psychologist Robin Dunbar initiated the social brain hypothesis, the idea that humans developed their large brains to cope, not with predators or competitor species, but with themselves. All higher primates spend a good half of their time keeping tabs on such key survival data as who is ascendant and who is sleeping with whom.
So how big a network can we handle? About 150, calculated Dunbar. It’s a number that reverberates in human history: the approximate size of modern hunter-gatherer bands and agricultural villages from Neolithic times until the present, including contemporary Amish settlements; the size of effective military units; the number of employees a company can manage without rigid hierarchies; even the number of Christmas-card recipients on a typical list. What it means today, says Dunkelman, “is that our capacity to reach out may be infinite, but our capacity to make something meaningful of it is not; we only have a certain-sized bucket of social capital, a limited number of cognitive slots.”