People and Language
The question of the ethnic, cultural, and linguistic identity of the Harappans has always generated debate, and in recent years the debate has been hijacked by groups determined to dictate a solution reflecting their own political or religious perspective rather than allowing the evidence to reveal the true picture.
A key point often overlooked in this debate is that languages, ethnic groups, and cultures are not and were not necessarily congruent. People from several ethnic groups may share a language, and, conversely, several languages may be spoken by people who are ethnically the same. Typically, when the speakers of two languages experience prolonged interaction and economic interdependence, there is a period of bilingualism during which each language influences and is influenced by the other. Eventually one language becomes dominant and the other may die out. Many factors may determine which language predominates; though numerical superiority may prevail, more usually it is the language of those who wield economic, political, religious, or military power that is adopted by those who wish to better their position.
Similarly, people of different ethnic backgrounds and speaking different languages may belong to the same cultural entity, while groups sharing a single ethnic makeup and speaking the same language may be culturally distinct. For example, there were many different ethnic and linguistic groups within the Roman Empire, all considering themselves to be Romans.
It is therefore a mistake to view South Asian prehistory as the story of monolithic blocks defined by the language they spoke. Over the millennia many languages have been introduced to the subcontinent and some have gained lasting currency; outsiders have arrived, both peaceful settlers and violent invaders, and have been assimilated; new cultural ideas have been introduced, some have been adopted from outside, and many more have developed within the subcontinent itself, among the rich mix of its peoples. The picture has always been a complex one in which perceived cultural identity crosscuts many underlying and interwoven strands of ethnicity, language, and religion.