•This is a feature of all scale-free networks made of directed, non-reciprocal links, according to Sergey Dorogovstev, Jose Mendes, and A. N. Samukhin.
•
•Watts points out that
friendships themselves are not
symmetric; usually there is a
superior/subordinate relationship. An
acquaintance of lesser prominence
is quicker to claim someone as a friend than someone
of high status.