In the sites of Harappa and Mohenjo-Daro, archeologists have found a high degree of standardization of weights, measures, architectural styles, and even brick sizes. Such standardization may suggest that

There might have been a central authority powerful enough to reach all corners of the society.

Explanation:

Harappa and Mohenjo-daro became the two great cities found in the Indus Valley Civilization. Harappa was known to be the first city in that region that archaeologists found. It was in the discovery sites of Harappa and Mohenjo-Daro, that archeologists found a high degree of standardization of weights, measures, architectural styles, and even brick sizes.

Therefore, this implies that there might have been a central authority powerful enough to reach all corners of society.

The Harappans became the first to develop a system of uniform weights and measures. These weights and measures conformed to a successive scale.