The Economist recently had an article titled: "Primates on Facebook," which suggests that even with social networking tools like Facebook and Twitter they still don't change the fact that 'the size of the human brain allows stable networks of about 148. Rounded to 150, this has become famous as “the Dunbar number”.'

I first became aware of the Rule of 150 after reading about it in Malcolm Gladwell's book: The Tipping Point (a great book that I highly recommend by the way). When I mentioned this article on Facebook one of my friends quipped: 'Said the man with 455 "friends."' Sure I may have a lot of connections on Facebook and LinkedIn, but I see the Rule of 150 as being a description of your core network. Certainly we've all met more than 150 people, we may even have quite a few more legitimate relationships than this theoretical 150 person limit. However if you really boil it down to the truly meaningful relationships I would image that you, like me, would come up with a number really close to 150.

Your core network in my opinion is your real network. These are your family, close friends, co-workers that you're close to, etc. The people you spend most of your time with, and have really solid relationships with. This certainly wouldn't include that guy you see a couple of times a year at this event or that event. It probably doesn't even include people you've had lunch or drinks with once or twice. These are the individuals you really spend time with, and who spend time with you where you have much deeper relationships.

So here's an interesting exercise I've been playing with. Exactly who makes up your core network? Who are these 150 people? Are they the right 150 people? There's also the theory that says you're most likely to be like the people you spend the most time with. It's probably a smaller subset of the 150 that this theory applies to, but it's an important concept to pay attention to.

Consider making an actual list to get a better understanding of what your own core network looks like.

That's just my 2 cents. What do you think? I'm very interested in your thoughts and comments.

Happy Networking!

Scott Ingram
NetworkInAustin.com

P.S. I'm considering writing a follow-up post. Something along the lines of: Beyond the Rule of 150 - The Impact of Social Networking Tools on Network Size. I have some definite opinions, but don't want to taint your thoughts with mine... yet. :)