The Indo-Aryan peoples or the Indic peoples are a diverse collection of ethnolinguistic groups speaking Indo-Aryan languages, a subgroup of the Indo-European language family. There are over one billion native speakers of Indo-Aryan languages,[not verified in body] most of them native to the Indian subcontinent and presently found all across South Asia, where they form the majority.[note 1]
Some of the theories proposed in the 20th century for the dispersal of Indo-Aryan languages are described by linguist Colin Masica in the chapter, "The Historical Context and Development of Indo-Aryan" in his book, The Indo-Aryan Languages.
A recent Indo-Aryan migration theory[note 2]—proposed by anthropologist David W. Anthony (in The Horse, The Wheel and Language) and by archaeologists Elena Efimovna Kuzmina and J. P. Mallory—claims that the introduction of the Indo-Aryan languages in the Indian subcontinent was a result of a migration of people from the Sintashta culture through the Bactria-Margiana Culture and into the northern Indian subcontinent (modern day India, Nepal, Bangladesh, Pakistan and Sri Lanka). These migrations started approximately 1,800 BCE, after the invention of the war chariot, and also brought Indo-Aryan languages into the Levant and possibly Inner Asia and western China.
The Indo-Aryan migration was part of the diffusion of Indo-European languages from the Proto-Indo-European homeland, either at the Pontic steppe or from a region between Armenia and Iran, which started in the 7th to 4th millennia BCE.
The theory posits that these Indo-Aryan speaking people may have been a genetically diverse group of people who were united by shared cultural norms and language, referred to as aryā, "noble." Diffusion of this culture and language took place by patron-client systems, which allowed for the absorption and acculturalisation of other groups into this culture, and explains the strong influence on other cultures with which it interacted. The Proto-Indo-Iranians, from which the Indo-Aryans developed, are identified with the Sintashta culture (2100–1800 BCE), and the Andronovo culture, which flourished ca. 1800–1400 BCE in the steppes around the Aral sea, present-day Kazakhstan, Uzbekistan and Turkmenistan. The proto-Indo-Iranians were influenced by the Bactria-Margiana Culture, south of the Andronovo culture, from which they borrowed their distinctive religious beliefs and practices. The Indo-Aryans split off around 1800-1600 BCE from the Iranians, whereafter the Indo-Aryans migrated into the Levant and north-western India.
The alternate Indigenous Aryans theory places the Indo-Aryans languages as being entirely indigenous to the Indian subcontinent and later they spread outside the subcontinent; this theory is currently rejected by mainstream scholarship.