What is Dunbar’s Number?

Years ago, I became intrigued when learning about something known as Dunbar’s Number. Dunbar’s number kept finding its way into news articles and radio interviews in discussions about social media, but what is it?

To quote Wikipedia, “Dunbar’s number is a suggested cognitive limit to the number of people with whom one can maintain stable social relationships—relationships in which an individual knows who each person is and how each person relates to every other person.” Dunbar’s Number is 150.

Let me give a quick disclaimer, Robin Dunbar is a professor of evolutionary anthropology at the University of Oxford, England. He is a naturalist and has an evolutionary worldview. Nevertheless, the data is helpful when considered from a Biblical worldview. His studies have shown that beyond 150 people, humans have a much harder time keeping track of each other.

There’s another aspect of our social interactions that some refer to as social layers. One study by Dunbar and his team was done using the phone data from six billion calls by thirty-five million people. The results are interesting.

In modern slang, there is a maximum of five BFF’s or besties in your life in the closest social layer. The next is your pals, not as close as your besties and that number is ten – give or take a few. So now you’re up to fifteen.
The next layer outward is your acquaintances, which are around thirty-five people. Now we’re up to about fifty altogether. Only five of those are people you are in regular interaction with, another ten less so, then there’s the thirty-five who you have less interaction with.

Remember, this is based on phone data not digital social media. You have actually talked with the person. Beyond that fifty, the other hundred in Dunbar’s number of 150 are people you rarely talk to but in the course of a year, you may call them, or they might call you at least once.

I realize that this generation has gravitated towards instant messaging and texts for communication. This non-verbal interaction might be your preference, but it is proving to be a substandard way of developing good relationships. This is a problem if it is the default rather than supplemental to preferred means, like in-person, or a facetime call, or a phone call.

Cultivating a few deep relationships is not only practical and essential for our lives but it was also modeled by Jesus. He taught multitudes of people on occasions but most of His time was spent with twelve disciples. Out of the twelve, there were three who spent extra time with Him. It looks like Robin Dunbar only lately discovered what Jesus already knew.