This discussion of race, however, tells us little about peoples in historical times or the present, when physical characteristics have been mixed.
The management of marked regional diversity, in the absence of an established political infrastructure, would have been especially challenging to the earliest efforts at a real hegemony by the Medes and the Persians.
One may presume that tribal organization continued to be the basis of social forms in both villages and pastoral groups, and we can begin to speak of linguistic divisions; some clans may have developed dialects of a shared tribal language. might be reconstructed, from cuneiform sources of Mesopotamia and from later relics, as follows: in the southern plains (Khuzestan) were the Elamites (see ELAM), who extended to the east perhaps as far as Sistān and in the north possibly to the Alborz mountains.
What was the population of the plateau before the coming of the Aryans? A general picture of the peoples of Iran at the beginning of the second millennium B. It would be more accurate to say that Elamite culture and influence reached so far, as may be inferred from remains of material culture and traces of proto-Elamite writing.
The earliest evidence of human habitation reveals that the people of the present countries of Iran and Afghanistan were overwhelmingly Caucasian in race with little trace of Negroid or Mongoloid mixtures.
Applying the cephalic index to Caucasoids in Europe, we find that in the north the population was predominantly long-headed or doliocephalic, sometimes designated as Nordic, while in Middle Europe the majority of people were round-headed or mesocephalic, also called Alpines (Coon, 1971, passim).