Saved by Ian Vanagas
The Dunbar Number as a Limit to Group Sizes
average network size was around 125, with a distinct ∩-shape against age: networks initially increase in size as we age, reach a peak between the mid-twenties and early thirties and then decline steadily into old age
Robin Dunbar • Friends: Understanding the Power of our Most Important Relationships
But even gossip has its limits. Sociological research has shown that the maximum ‘natural’ size of a group bonded by gossip is about 150 individuals. Most people can neither intimately know, nor gossip effectively about, more than 150 human beings.
Yuval Noah Harari • Sapiens: A Brief History of Humankind
it was the size of the community that was nearest to 150.
Robin Dunbar • Friends: Understanding the Power of our Most Important Relationships
there was an upper limit at four on the number of people actually engaged with each other in a conversation and an upper limit at around three on the number of people who laughed together during a conversation.