Any group has an organized structure which is well defined .e.g. The class is an organized structure which is homogeneous with respect to age, subject, etc. 6. Motivation Mutual Obligation - The degree of motivation or the motivational level that exists among the members of the group should be the same. It is such a power as keeps not only the members of the group united but also provides them with energy e.g. the relationship between the children & parents in the family or the love of husband & wife. In spite of differences, they have certain common aims, ideals & values. We-feeling is developed leading to the development of affinity in the group. Social values are also developed.