Just Call Me Greek, or is that Athenian..
If you lived in ancient Greece you identified yourself as Greek. You and everyone around your spoke the same language and worshiped the same gods. You all shared a common history. But before you identified with being Greek, you claimed allegiance to your polis.
Their polis, or city-state, was where ancient Greeks really drew their identity. Poli were comprised of a central city and its surrounding farmland and property. Each city-state was self-governing and due to the mountainous terrain of Greece it was a rather hard journey from one polis to another. For these two main reasons looked upon all Greeks as cousins, in a sense, but to members of their own polis as brothers.
There were four main city-states in ancient Greece that held most of the power. While it is true that members of all poli considered themselves Greek, that does not mean they always got along. There was often fighting and competition among city-states, particularly the two most powerful: Athens and Sparta. It's more accurate to view ancient Greece as more of a strongly bound confederacy than a true nation.
When most people try to envision ancient Greeks, they're really trying to envision an Athenian. Athens was the Greek hub of culture, art and science. Schooling here is more extensive than any other city-state in Greece, and most often when outsiders want to deal with Greece as a whole, they treat Athens as a capital. Of course this is perfectly natural in an Athenian's eyes. After all, it's the scholar and thinker that leads a people, is it not?
To be Spartan is to be a soldier: cunning, fierce and willing to win at any cost to yourself or others. Military life was literally invented by these people. Boys were taught to be fierce: food was barely rationed and a growing boy had to steal food to thrive. But if caught stealing a boy would be beaten. The lesson being taught here was to survive on your own. Though most city-states didn't particularly like them, all but Athens openly admitted their use. In times of war there were no other soldiers you would rather rely on than Spartans.
Corinthians are the practical entrepreneurs of the ancient Greek world. Corinth is a coastal polis, so trade quickly became of great import. Though culture and science were taught nearly as well here as in Athens, trade and commerce were the true way of life. These Greeks developed their own coinage for the express purpose of easier trade. They made any traders convert their money for a fee before trading so as to streamline the process (and make some extra money!) The Corinthians also implemented the first public works programs to deal with unemployment.
Argos had nothing really going for it in the begriming. They were not as smart as the Athenians, nor as fierce as the Spartans. They were on one of Greece's few barren plains as well, so farming was hard. So the Argives decided to break into show business. Argos produces many of the great poets, playwrights and artists of Greece.All that come to your city-state marvel at its wondrous statues and brilliant plays constantly being given in open-air theaters.