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Dunbar's number Syllabification: Dun·bar's num·ber
(also Dunbar number)

Definition of Dunbar's number in English:


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
  • Second, to summarize, Dunbar's Number says that we can only have a fixed number of relationships in life.
  • Lately, Dunbar's number has been taken as a mean size for online networks and groups.
  • Technically "Dunbar's number," a theoretical limit that pegs the number of social relationships one can maintain at somewhere between 100 and 230, applied to everyone, but I couldn't help but take it personally.


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

Definition of Dunbar's number in:

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