Note, also, that the writer has indicated the organization of the document, as well.
The primary role of a general statement is to support your thesis.
In the introductory paragraph, general statements can also build up to your thesis by providing relevant background.
In a sociology paper, your thesis might argue that childhood poverty is the best predictor of adult poverty.
General statements might then give facts about childhood poverty, statements about how to end poverty or information on the psychological ramifications of poverty.