This chart caught my eye yesterday:
It’s from Robin Dunbar’s recent book, Friends: Understanding the Power of Our Most Important Relationships. You might recall the author’s name from his concept of Dunbar’s number:that on average people can maintain about 150 friendships with others, a limit that is determined by human brain size and function. The chart is a more detailed version of the concept: it shows, roughly, the number of people we can have meaningful relationships with at various levels of intimacy. Dunbar explains in this Atlantic interview:
The innermost layer of 1.5 is [the most intimate]; clearly that has to do with your romantic relationships. The next layer of five is your shoulders-to-cry-on friendships. They are the ones who will drop everything to support us when our world falls apart. The 15 layer includes the previous five, and your core social partners. They are our main social companions, so they provide the context for having fun times. They also provide the main circle for exchange of child care. We trust them enough to leave our children with them. The next layer up, at 50, is your big-weekend-barbecue people.