How Many People Do You Know?

From Harvard Business Review's Daily Stat:

FEBRUARY 27, 2013

Your Acquaintances Would More Than Fill Two Boeing 787s

Each adult American knows, on average, 600 people, Andrew Gelman of Columbia University writes in The New York Times. The estimate is based on an ingenious method: Asking a sample of individuals how many people they know with a variety of memorable names such as Brenda and Keith (because people with such names are easily recalled), then factoring in the prevalence of those names in U.S. society. Despite the large number of acquaintances, most Americans know just 10 to 25 people well enough to trust them, Gelman says.

Source: The Average American Knows How Many People?