Social networks members only interact with 5-10 percent of their network, claims Facebook’s in-house sociologist Dr. Cameron Marlow in an interview with the economist.

“Dr Marlow found that the average number of “friends” in a Facebook network is 120, consistent with Dr Dunbar’s hypothesis, and that women tend to have somewhat more than men.”

Dr. Robin Dunbar is an anthropologist who now works at Oxford University. A few years ago he concluded that the cognitive power of the brain limits the size of the social network that an individual of any given species can develop. The limit is 150 connections and has become known as “the Dunbar number”.

The Facebook sociologist puts out numbers according to which the average male Facebook user with 120 friends leaves comments on 7 friends’ photos, status updates, or wall and messages or chats with 4 friends. Female users’ numbers are slightly higher.

It all connects to some recent studies which claim, that the social networks apparently didn’t create the expected increase in the number of our social connections. No one claims it’s the social networks’ fault but researchers do claim there is a decrease in the number of the real-life, active, social connections we manage today.

Are the social networks a disappointment? Not necessarily. They can contribute to the number of casual contacts a person has. They may contribute to better self advertising of individuals, the economist article claims, but don’t expect them to fundamentally change the structure of the brain, allowing human beings to manage actively a larger number of connections.

This article got me thinking. I thought about the Facebook findings and decided to check my own statistics and network behavior.

I am not sure they have what it takes to properly analyze connections management. For instance, 9% of my 289 people network on Facebook is made of family members. An additional 10% are close friends or business associates. With all of those I keep an active connection outside of Facebook. So for me at least, the Facebook activity is mainly aimed at nurturing and growing relationships that are “networking relationship” to begin with, what the statistics refer to as casual connections.

Going back to exploring the current state of our human networking conditions. The Dunbar number is probably correct. And it could be that people today manage less “real and active connections”. And yes, it could be the social networks’ fault. Because they are overwhelming us with opportunities that start off as casual connection, and given the correct grooming, can become a real-active-connection.

Let’s check back in 5 years.