Interview with Robin Dunbar, of "Dunbar's number". Besides the famous 150, there are other numbers of note: > The distribution of the data formed a series of l

Interview with Robin Dunbar, of "Dunbar's number". Besides the famous 150, there are other numbers of note: > The distribution of the data formed a series of layers, with each outer layer including everybody in the inner layer. Each layer is three times the size of the layer directly preceding it: 5; 15; 50; 150; 500; 1,500; 5,000.