However, in South Asian studies the concept of an Indo-Aryan invasion continues to be the main explanation for the cultural history of that region. T… - Jim G. Shaffer

This review of archaeological data demonstrates that a continued division of South Asian cultural history into discrete archaeological “cultures” or “sta­ges” such as non-Harappan, “early” Harappan, “mature” Harappan, Kot Dijian, “late” Harappan, Painted Gray Ware and others masks the existence of a long surviving cultural tradition, and distorts the processes responsible for the cultu­ral changes this variety of designations represents. Archaeological data indicate the existence of a long-term cultural tradition responsive to changing cultural and ecological contexts, with an ability to adjust to rapid, as well as long-term, changes.

“No material culture is found to move from west to east across the Indus”. [in the relevant time period]

Lacking fullest data, there is, nonetheless, a growing consensus that Harappan culture is the result of indigenous cultural developments, with no “Mesopotamian” people or diffusions of Western inventions, by whatever means, needed to explain it.