Social network theory is a label that stands for a great variety of theoretical and empirical approaches. Unfortunately, the theory is still underway. Precisely, all the research programmes are still in their spring. For instance, the experimental designs testing different hypotheses, designate the social network structures as as being given (or assumed to pre-exist). This is, for sure, an important issue, as in the "real life", you should not make such assuptions. The social networks are dynamic and it's hard to say which configuration comes first in the line.