At Harappa, there is evidence for matrilocality - where husbands go to live with their wives' community.
Nearly all cemetery inhumations conform to a similar layout that is not readily differentiated into distinct social classes.
The skeletons found are generally healthy people which indicates an improved access to resources. A study found that the few burials that have been found (only 600 so far across hundreds of years of urbanized living across hundreds of settlements) may have related to first generation immigrants. These burials show they were respected and that mobility between villages and cities existed as also trade. Joe Ravi, CC-BY-SA 3.0, Wikimedia
A study from Farmana, in present day Haryana, showed trade links with present day Punjab in Pakistan, and Gujarat as well. There were signs of matrimonial linkages as well.
More burials found at Rakhigarhi at Haryana have unearthed a man and a woman together, possibly in a matrimonial relationship. This may point to the earliest marriage (4700 years ago) for which evidence has been found.
Uptill now historians believed the earliest marriage had taken place about 4400 years ago, in Mesopotamia.
Historians believe that some of the beautiful painted jars found at various sites may have been used as marriage gifts.
A bangle found at Susa in ancient Mesopotamia was made from materials found only along the Indus coast. Historians have speculated that 'it is possible that the woman wearing this bangle was part of a marriage alliance with a distant trading family in Susa. Such long distance marriage contracts can be documented historically and ethnographically. In the absence of strong state control, long distance kin relationships would have been a form of insurance in trade relations.'