Why is it difficult for historians to study early human societies

Because there are not enough organised data

Explanation:

During those early societies, they were not organised, so the information that was left over for the next set of generation that will inherit the land was not enough and organised for them to assess and study for them figure out who were the early settlement of the land, due to the fact that they were not organised, this affected the collection of data.

Before the advent of writing, historians had fewer and less detailed resources to work with

Explanation:

answer; nonpartisan election;