You Can Only Have About 150 Friends At A Time

You Can Only Have About 150 Friends At A Time

These days, it's not unusual for someone to have more than 1,000 friends on Facebook. But it's unusual that anyone could actually maintain a real relationship which each of those people. In fact, according to anthropologist Robin Dunbar, a person can only keep up relationships with 150 people at a time. Dunbar's number, which was proposed in the 1990s, is meant to include those with whom a person has a maintained social relationship, and excludes anyone who has fallen out of touch or is a fairweather friend. Theoretically, the human brain would be incapable of remembering and categorizing many more than 200 people, due to the limited processing ability of the neocortex. Learn more about the possible size of your social network with the videos below.

The Science Of Dunbar's Number

How did 150 become the magic number?


Key Facts In This Video

  • 1

    A stable social relationship is one that exists over an extended amount of time. (1:06)

  • 2

    Anthropologist and evolutionary physiologist Robin Dunbar speculated that we can only know 150 people on average. (1:56)

  • 3

    Dunbar's Number does not carefully consider relationships that solely exist online. (2:21)

How Many Friends Do You Need?

Science says you can have 150, but do you really need that many?

Robin Dunbar On His Magic Number

The anthropologist speaks to the science of relationships.

See all


Social Behavior


Nikola Tesla

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