Definition of Dunbar's number in English:

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Dunbar's number

(also Dunbar number)


A theoretical limit to the number of people with whom any individual is able to sustain a stable or meaningful social relationship (usually considered to be roughly 150): even in the age of Facebook, the number of friends with whom you keep in touch is likely to be less than Dunbar’s number
More example sentences
  • The Dunbar number probably dates back to the appearance of anatomically modern humans 250,000 years ago.
  • The second category of respondents (28 percent) follow more than 250 feeds, which is much higher than the Dunbar number.
  • Recall that the Dunbar number is what you can manage with your own faculties, so somehow you are cognizant of your active network.


Early 21st century: named after Robin Dunbar (b. 1947), the British anthropologist and psychologist who proposed the theory in the 1990s.

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