Facebook Research: Socializing doesn’t Scale

Facebook research shows that people have an average of 150 friends, supporting the existence of “Dunbar’s Number” which I wrote about in a previous post on why socializing doesn’t scale. The same research also supports the existence of a support clique of 3 to 5 people, as Facebook users have on average 5 close friends they spend most of their time interacting with.

The TEDxObserver presentation below shows Robin Dunbar discussing this research.



  1. […] traveling faster from individual to individual. However, this effect is so massive, that many are fooled into describing rapids spreads as “viral”. However, viral spreads implies social […]

    Pingback by How To Scale Social Media Marketing — April 14, 2012 @ 3:18 am

  2. If the numbers game sounds tawdry to you, you’d fit in with the U.K. researchers, who are looking at the effects of such friend-hoarding. “The cheapness of communication is a double-edged sword,” Dr. Reader says. Whereas you might enrich your life with more contacts, the things that are “important for intimate friendships,” such as presents, meals and a ride in your car, he says, don’t exist.

    Comment by Craig E. Phillips — February 17, 2013 @ 1:46 am

  3. Working with the anthropologist Russell Hill, Dunbar pieced together the average English household’s network of yuletide cheer. The researchers were able to report, for example, that about a quarter of cards went to relatives, nearly two-thirds to friends, and 8 percent to colleagues. The primary finding of the study, however, was a single number: the total population of the households each set of cards went out to. That number was 153.5, or roughly 150.

    Comment by Dion N. Stevenson — May 19, 2013 @ 10:02 pm

  4. When people first join Twitter they have few friends. As time goes by the data shows they acquire more friends, but the number of replies they send to other users will increase consistently only in stable social situations. Eventually they reach a point where the number of contacts surpasses their ability to keep in contact.

    Comment by Marsha Y. Gallegos — May 20, 2013 @ 5:52 am

  5. Well, if his hypothesis is validated this number should still apply to modern humans. You always have to remember that for 99% of our species existence we lived in groups of 150-250 individuals. Because biological evolution operates on very long time scales our bodies and brains are really still adapted to a hunter-gatherer lifestyle. This is also the case because natural selection does not operate on our species in the same way as it did throughout most of our evolution anymore (e.g., because most people live long enough to reproduce). Dunbar’s number makes sense when you think about your own life. I know it does when I think about my own. How many relationships do I maintain (to any degree) at any one time? It certainly isn’t more than 150. It takes up a lot of mental power to maintain social relationships. They are complicated and we only have so much space in our neocortex to handle that much information. It shouldn’t surprise anyone that there is some limit on the number we can functionally maintain. That being said, how many practically do we need to maintain? Social relationships also take up a lot of time and energy. At some point we have to conduct a subconscious cost/benefit analysis when evaluating who is in our life and who isn’t in our life. It would be practically impossible to maintain relationships with 1,000’s of individuals. Dunbar’s number has evoked a ton of controversy and interest. It is certainly an engaging idea that will require more research to solve.

    Comment by Shelby Dotson — May 25, 2013 @ 12:23 pm

  6. Dunbar’s number isn’t fixed. It can be increased or decreased depending on the environment and tools you have available. You most likely have a much smaller group of friends than 150 people, but when you are incentivized to connect to more people than you would naturally associate-like at your job or in a school-150 is the point where your neocortex cries uncle. With better tools-like telephones, Facebook, World of Warcraft guilds and so on, you become slightly more efficient at maintaining relationships, so the number can be larger, but not much larger. Dunbar’s most recent research suggests even power-users of Facebook with 1,000 or more friends still only communicate regularly with around 150 people, and of that 150 they strongly communicate with a group less than 20.

    Comment by Ignacio Alvarez — June 8, 2013 @ 7:31 am

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