Being a biologist and a true follower of evolution theory I think that all social things are just the means of human adaptive changes, just as language itself. It is another strategy from those used by other living beings: instead of adapting to new climat, food etc. we chose to adjust our adaptivness to excellence, having a highly organized society with the means of communication, division of labour etc. For example, for aphis it is necessary to evolve to new species just to start eating another plant, but we, people, can try new food everyday and our means of cooking can convert even most poisonous foods to edible meals.
I do not know about "scienceness" of sociology, psychology and such, but linguistics and anthropology are totally science for me.
I'm sorry for my not very clear explanations, but my English somewhat restrains me from good scientific language.