Therefore, the entropy is a magnitude to consider when we analyze the properties of the temporary evolution of social systems, even the divergent ones to each other. Mathematically, the entropy is the average value of the car information (also called subjective information), and this one, referred a social event is defined mathematically thus: I (Ax) = – log (px) is not our intention to crush to the reader with complicated algorithmic calculations. To only show that in as much perceivable social phenomenon, the entropy also owns characteristics that can be quantified and that give ponderable consistency him to their quality: It is a magnitude. But in the entropic analysis of the behavior of the social groups it is necessary to consider a variable supreme important: the diversity. Ramon Margalef beside the point contributes a wonderful approach to us on this concept: " The diversity is an expression of the resulting structure of the form in which the individuals of the system interact social". The diversity, then, not only explains the epistemologic foundation of the entropy, but it is transformed into a necessary element in the support of a complex social structure: If the social diversity is reduced, the possibilities of maintaining social a structure complex are reduced, if the diversity is very elevated, will be difficult to maintain the functionality of the social apparatus, unless other properties of the social structure modify suitably. For many social analysts and psychologists a very close relation between the social diversity and the form exists in which the different structures from the social system are related to each other. It can be expressed by means of a connectivity measurement. One has demonstrated that a clear decreasing relation in the social equation exists: greater social diversity smaller connectivity between its members, but in more recent investigations on social mobility, structure and group behavior is observed a relation still more accused between the number of individuals and the connectivity.