Humans can only manage about 150 relationships

Even online

(src: Video: Start With Why - Simon Sinek)

inner circle

3-5

very close friends or family members

sympathy group

7-10

close friends who care about each other's fate

hunting group

30-50

collegues who care about each other's fate

-how much it takes to achieve a goal

clan

100-150

people who maintain stable inter-personal relationships

-everybody knows eachother

-peer pressure works

tribe

500-2500

people who speak the same language or dialect

(src: Video: The Scaling Dilemma - Mary Poppendieck # Model: Ideal Team Size)

Model: Dunbar's number

Dunbar’s number (after anthropologist Robin Dunbar). Dunbar found fifteen to be the limit of the number of people one person can trust deeply.5 From those, only around five people can be known and trusted closely

Allowing teams to grow beyond the magic seven-to-nine size imperils the viability of the software being built by that team, because trust will begin to break down and unsuitable decisions might ensue.

(src: Book: Team Topologies - Matthew Skelton & Manuel Pais)