To understand the most important characteristics of a society, one must study its major cities.

The characteristics of a society correlate well with the general characteristics of every each individual in that society. For example an industrious society primarily consists of hard-working persons. To study a society, one should choose a sample population which reflects the whole society in almost all aspects of it.

Considering the significantly variable groups of people, who live in major cities, they may well represent the principle characteristics of the considered nation. While minor cities may suffer from some deprivations, major cities, with the wide variety of civil facilities, high-income job opportunities, and flamboyant entertainments, attract diverse groups of people to them. For example, Tehran, which is the Capital city of Iran, has millions of residents who are from all over the country. It is to some extent the same in other major cities such as Isfahan and Mashhad.

On the opposite side, there may be an argument that life style in major cities may be totally different from remote or rural areas and some traditions might be intentionally abandoned there. However, it is totally nonsense to postulate that major city residents are socially isolated or far apart from residents of other parts of a country. When considering a whole nation as an individual character, nobody looks for minorities and minute deviations but for what the society has in common. These common and, of course, pivotal manifestations of a society, which approximately are constants of a society, primarily indicate how the mentioned people perceive life, how manage to live and how may counteract to other societies.

Thus, it is reasonable to assert that major cities should be studied for understanding the most important characteristic of a society such as attitude toward life, cultural diversity, social inter-relations, religious believes, and etc.