Not really care for, but the number of relationships you can keep track of: "By using the average human brain size and extrapolating from the results of primat

Not really care for, but the number of relationships you can keep track of: "By using the average human brain size and extrapolating from the results of primates, he proposed that humans can comfortably maintain 150 stable relationships." https://en.wikipedia.org/wiki/Dunbar%27s_number https://en.wikipedia.org/wiki/Dunbar%27s_number