Can the Brain be the Limitation of Social Connections?
According to an article written on The Physics arXiv Blog entitled “Human Brain Limits Twitter Friends to 150 ” , your brain restricts you to on average 150 friends.
The article explains this prediction made by British anthropologist Robin Dunbar in the early 90’s after monitoring social interactions amongst primates. He theorized that the volume of the brain is directly linked to the amount of people you can maintain social contact with. Obviously, when we say friend, we are not referring to everyone who “follows” you or “friends” you in social networks, but people in which you actually have a deep link with. Bruno Goncalves and some colleagues from Indiana University were given access to Twitter for 6 months during which they reviewed 3 million Twitter users over the course of 4 years
Their results?  The average of those users monitored could keep meaningful social interactions with between 100 and 200 people, which roughly agrees with the Dunbar number of 150.
After reading the original research paper (which I encourage everyone to do) and corresponding data, I found I am curious about some of the conclusions, namely dealing with the weight (designated as ω out) as a representation of how strong a friendship is. It is calculated by a formula that takes into consideration the number of replies between 2 people in a conversation. The higher the weight, the stronger the friendship.
As seen in the graph, a maximum weight is achieved when a user has between 100 and 200 outgoing links, or simply, when a user responds to 100-200 people regularly.
In looking at the interval between 0 and 100 in which the average weight of each connection is between 5 and 6, it is interesting to see the weight seems to increase over the initial period as a user gains more contacts. This could just be an artifact of a “new user effect”, or a learning curve when a new user first starts using Twitter and not an actual result of social interaction of people with less than 100 friends.
The range of 100-200 friends is also interesting in that it just barely passes the peak weight of 6. Afterwards, the weight does not drop below 5 until almost 350 outgoing contacts, and it doesn’t stay below 5 significantly until about 500 outgoing contacts. While the peak relations as defined by the study do indeed occur between 100 and 200 friends, there is still a substantial amount of people maintaining almost as strong connections with up to 500 people.
Still, in the end the research seems to be well done, and it is interesting to see how close the Dunbar prediction is to real life scenarios. The question remains however, is this a maximum number restricted by our brains as Dunbar predicts, or will new technology and time slowly expand our social abilities?