What is the term sociologists give to a category of people with a common characteristic, usually their age?.

Peer group.

Explanation:

A social group in which members are usually the same age and have interests and social position in common.

the first settlements began along the huang river because of the importance of the huang river in the beginning of china. it goes back to the story, “the tale of emperor yu”, which references the tale of the great flood, which was caused by the huang river and was believed to create and influence china’s making.