How many people can we know?

150.

See the explanation after the jump.

From The Oklahoman:

Q: Can you propose numbers and perhaps even a sort of formula for maintaining human friendships?

A: The magic number is about 150 for the natural size of social groups, according to University of Oxford’s Robin Dunbar, as reported by Catherine deLange in New Scientist magazine. This number is even in the right ballpark for modern online groups.

“Facebook allows up to 5,000 friends, but most users have between 150 and 250, although many of these will be acquaintances and some will be strangers.” Actually, people with more Facebook friends tend to have more in-person friends as well.

As for a friendship formula, Dunbar suggests everyother-day contact for your very close friends and once a week for your next five closest pals, either face-to-face or online. Once a month is enough for the next 15, every six months for the next 50, and once a year for the rest of the group.

The exception is close friendships from your younger days — “you can often pick these relationships up exactly where you left off, even after decades.”

For more on the “Dunbar Number,” go here.

I resist quantifying such things.  Still, could this research help us to see what the optimum size might be for, say, a church?  (After reaching this number it could split into two congregations.)