dogmom, BecLak, normal in social psychology, is defined as norms. They are constructed by the social behavior maintained by the dominant groups in any culture. In some ways, laws are constructed by social norms. If you steal a car, more people think you should be punished for your actions or go to jail. That is a norm and laws are created off what the norms align towards.
Applies to social aspects too, to be skinny, slim women, strong muscled men with six packs, and so on. Norms are influenced by those (dominant groups) around us that keep it going.