You are going to have a very hard time selling that theory. The world is a vastly more fair and less savage place now then at any other point in human history.
I'm sure folks in Syria would disagree.
That's the result of technology, not moral standards. People are the same as they've always been, and I'd describe the moral evolution as a random walk, more than anything.
That's an extremely broad statement. Do you really know that much history?