A new civilization came into existance with the arrival of Aryans. Slowly each occupation became inheritance. The people belonging to different castes did not get marry to each other. Women were not given share in the property. The local community had become their slave.
ARYANS. Definition of the term “Aryan.” The name “Aryan” (OInd. āˊrya-, Ir. *arya- [with short a-], in Old Pers. ariya-, Av. airiia-, etc.) is the self designation of the peoples of Ancient India and Ancient Iran who spoke Aryan languages, in contrast to the “non-Aryan” peoples of those “Aryan” countries (cf. OInd. an-āˊrya-, Av. an-airiia-, etc.), and lives on in ethnic names like Alan (Lat. Alani, NPers. Īrān, Oss. Ir and Iron. “Aryan” is thus basically a linguistic concept, denoting the closely related Indo-Aryan and Iranian languages (including Nūrestānī), which together form the Indo-Iranian or Aryan branch of the Indo-European language family, sharing a linguistic and cultural development separate from the other IE. tribes. The use of the name “Aryan,” in vogue especially in the 19th century, as a designation of the entire Indo-European language family was based on the erroneous assumption that Sanskrit was the oldest IE. language, and the untenable view (primarily propagated by Adolphe Pictet) that the names of Ireland and the Irishmen were etymologically related to “Aryan.” (For the Iranian attestations of the word, see H. W. Bailey on Arya above. For the etymological problems see also H. Siegert, “Zur Geschichte der Begriffe “Arier” und “arisch”,” Wörter und Sachen 22, N.F. 4, 1941/42, pp. 73-99. M. Mayrhofer, Kurzgefasstes etymologisches Wörterbuch des Altindischen I, Heidelberg, 1956, pp. 49, 52, 79; III, Heidelberg, 1976, pp. 623, 633f.)
The Aryan parent language. The common ancestor of the historical Aryan or Indo-Iranian languages, called the Aryan parent language or Proto-Aryan, can be reconstructed by the methods of historical comparative linguistics. The Indian group or Indo-Aryan (especially Vedic, the language of the Vedas), Avestan, and Old Persian show some remarkable correspondences, especially in the religious language (one could translate whole Av. sentences word by word according to the phonetic laws into correct Vedic). By comparison of the (Old) Indo-Aryan with the (Old) Iranian languages a Proto-Aryan language can be reconstructed, which must be counted as the most archaic of all IE. languages.
A number of exclusive innovations separate Indo-Aryan and Iranian from the other IE. language, e.g., (1) the merger of IE. *a, e, o and *ā, ē, ō into Indo-Ir. *a and *ā respectively (also in the diphthongs), (2) the development of IE. *ə into Indo-Ir. *i, (3) the change of IE. *s after *i, u, r, k into Indo-Ir. *š (Ir. *š, OInd. ṣ), (4) the gen. plur. ending *-nām in the vocalic stem classes, etc. In addition there are important correspondences in the vocabulary, especially in the field of religion and mythology, including morphological elements, such as suffixes and stem-formations, and phraseology. (See Chr. Bartholomae, “Vorgeschichte der iranischen Sprachen,” in Geiger and Kuhn, Grundr. Ir. Phil. I/1, 1895-1901, pp. 1-151. A. Erhart, Struktura indoíránských jazykûʷ [The structure of the Indo-Ir. languages], Brno, 1980.)