Facebook Statistics

What’s your Dunbar number? As Maria Konnikova tells it in the New Yorker, Oxford anthropologist Robert Dunbar calculates that the average human being has about 150 people in their social group (100 to 200 on average):

From there, through qualitative interviews coupled with analysis of experimental and survey data, Dunbar discovered that the number grows and decreases according to a precise formula, roughly a “rule of three.” The next step down, fifty, is the number of people we call close friends—perhaps the people you’d invite to a group dinner. You see them often, but not so much that you consider them to be true intimates. Then there’s the circle of fifteen: the friends that you can turn to for sympathy when you need it, the ones you can confide in about most things. The most intimate Dunbar number, five, is your close support group. These are your best friends (and often family members). On the flipside, groups can extend to five hundred, the acquaintance level, and to fifteen hundred, the absolute limit—the people for whom you can put a name to a face. While the group sizes are relatively stable, their composition can be fluid. Your five today may not be your five next week; people drift among layers and sometimes fall out of them altogether.

Dunbar argues that his formulas hold across human history around the globe, at which point we begin to drift from common sense into pop science. The common sense part is that there are only 24 hours in a day and 70 to 85 years in a normal human lifespan, which poses an absolute limit on how many people one could get to know.

The pop science part assumes that all cultures function like modern Western ones. In many times and places, women’s contacts have been severely restricted by cultural norms. After marriage, their lifetime companions were (are?) their husbands, mothers- and sisters-in-law, and any relationships that arise within that new family. Whether it adds up to 150 relationships or 15 is not governed by the woman’s cognitive capacity but by the limits imposed by her culture.

That said, Dunbar’s work raises an intriguing question whether social media like Facebook and Twitter have changed anything. As Konnikova notes, researchers generally found that the numbers of contacts remained constant—probably, one would think, because social media can make space disappear, but not time. As Dunbar notes, if we spend our time Liking and Friending, we aren’t building close relationships. That doesn’t mean nothing has changed:

“This is the big imponderable,” Dunbar said. “We haven’t yet seen an entire generation that’s grown up with things like Facebook go through adulthood yet.” Dunbar himself doesn’t have a firm opinion one way or the other about whether virtual social networks will prove wonderful for friendships or ultimately diminish the number of satisfying interactions one has. “I don’t think we have enough evidence to argue either way,” he said. More.

The rap against Facebook friends, of course, is that they are superficial. In my experience, that depends on the nature of the community. How is it formed?

I currently have 1210 Facebook Friends, most of whom I have never heard of. But that fact is irrelevant to how many people I can keep track of. To deal with the incoming stream of requests, I tend to Friend anyone who has one or more mutual Friends. I only post links to items I have just published anyway, for the convenience of whoever wishes to know about them.

On the other hand, when my recently widowed father moved from a retirement home in a distant city to one in my own city, the family started a very small Facebook page to record interactions with him as he adjusted to a new life. We all knew each other pretty well anyway.

Many pages, including ones where I post or even moderate (groan!), exist to thrash out issues of the day, for example Intelligent Design (currently nearly 7000 members.) Other pages are such personal affairs that one can deeply hurt people that one didn’t even feel very close to, by deactivating the page. (They think they have been Unfriended.)

There is an indefinite variety of purposes for a Facebook page. That makes it difficult to determine what effect Facebook truly has on relationships in any meaningful way. Here is a hopeful suggestion: Given that many people choose to “virtually scream” at each other on Facebook, it may reduce violence as well as warmth.

Considering that there are over 54 million Facebook pages, that may prove useful in the long run. 😉

Note: Here are some Facebook stats, including:

Facebook is the largest online social network. Founded in February 2004 by Mark Zuckerberg and fellow Harvard students Eduardo Saverin, Andrew McCollum, Dustin Moskovitz and Chris Hughes. In 2008 Facebook had 100 million users and as of March 2013 has 1.11 Billion. Facebook filed for a $5 billion IPO on February 1st 2012 and valued the company at $104 billion


Denyse O’Leary is a Canadian journalist, author, and blogger.

Denyse O’Leary is an author, journalist, and blogger who has mainly written popular science and social science. Fellow Canadian Marshall McLuhan’s description of electronic media as a global village...