Are there any general trends in the value of human beings of the course of world history?

A major theme is the value of humans as viewed in art across the time periods. Do you notice any general trends in the value of human beings since beginning of time? Are these trends dictated by events in particular or is there more of a consensus that is achieved gradually over time?

People have always been inherently valuable– even if only as slaves. In the very broadest sense, you can make a case that as democratic institutions increased, so did the perceived value of individual people. I think the consensus would be a gradual change over a long time and not equally in all places on the earth.