Human beings are only capable of keeping track of about 150 people at a time, well 148 to be exact. This is in reference to what I am learning is the famous “Dunbar’s Number“. A new acquaintance of mine recently dropped this reference while engaging in my current pet project of analyzing the impact of social networking technologies on humanity.

From my cursory investigation it looks like Mr. Dunbar studied the social habits of a bunch of primates and wrote up his findings back in 1992. Apparently he did some regression analysis on the size of a primate frontal cortex as compared to that of a human and was able to extrapolate from his data a “mean group size” of about 150. That is to say, the human brain has the limited capacity to track roughly 150 social connections at any given time.

Regardless of what you think about the value proposition of evolutionary biology research, I don’t believe anyone appreciates their human social habits being reduced to a multiplier of primate research data. But once you start to look back at the history of mankind in community, the figure of 150 starts to pull out as a viable deduction.

• Neolithic farming village, 150
• Roman army company size, 150
• Average protestant church size, 100
• Average number of FaceBook friends, 120

A little bit more e-research landed me at the following article from the Economist. This Economist article did some value synthesis and analysis on the issue that I found rather confirming to my suspicions. Even though people are “connected” to several hundred people, they can still only interact with focused attention on a handful of people.

Thus an average man—one with 120 friends—generally responds to the postings of only seven of those friends by leaving comments on the posting individual’s photos, status messages or “wall”. An average woman is slightly more sociable, responding to ten. When it comes to two-way communication such as e-mails or chats, the average man interacts with only four people and the average woman with six. Among those Facebook users with 500 friends, these numbers are somewhat higher, but not hugely so. Men leave comments for 17 friends, women for 26. Men communicate with ten, women with 16.

Even in the technology supercharged universe of social networking, I (being a typical guy) can only maintain a meaningful discourse with 7 or so people. I have found this to be true for myself, in many ways FaceBook has usurped the role of communiques that used to be handled by e-mail or a phone call with a few of my regular friends… its just the chosen mode of communication at the moment. Having contact information for these folks is important, and FaceBook certainly solves that problem.

But what is different is the environment that I am forced to enter into in order to send and receive these communications. And with that thought, I believe the Economist article did have some further analysis that begins to head towards a moral judgment and warning against social networking technologies.

What mainly goes up, therefore, is not the core network but the number of casual contacts that people track more passively.

…people who are members of online social networks are not so much “networking” as they are “broadcasting their lives to an outer tier of acquaintances who aren’t necessarily inside the Dunbar circle. Humans may be advertising themselves more efficiently. But they still have the same small circles of intimacy as ever.

We may accomplish a more successful marketing campaign of our social lives, but that has nothing to do with knowing each other deeply. If environments like FaceBook become the standard for communicating within our communities we may suffer the same passive atrophy that extended television watching habits have had on our ability to engage ideas and information in a meaningful way. Not to mention becoming fodder for the most ravenous collection of closed caption marketing experiments ever known to man.

Economist
http://www.economist.com/science/displaystory.cfm?story_id=13176775

Dunbar’s number
http://en.wikipedia.org/wiki/Dunbar%27s_number

Facebook stats
http://www.facebook.com/press/info.php?statistics

Categories: Social Networking, Technology, Relationships