I know of no study that measures whether the quality of moral debate has risen over the twentieth century. However, I will show why it should have. The key is that more people take the hypothetical seriously, and taking the hypothetical seriously is a prerequisite to getting serious moral debate off the ground. My brother and I would argue with our father about race, and when he endorsed discrimination, we would say, “But what if your skin turned black?” As a man born in 1885, and firmly grounded in the concrete, he would reply, “That is the dumbest thing you have ever said—whom do you know whose skin has ever turned black?” I never encounter contemporary racists who respond in that way. They feel that they must take the hypothetical seriously, and see they are being challenged to use reason detached from the concrete to show that their racial judgments are logically consistent.

James Flynn, Are We Getting Smarter? Rising IQ in the Twenty-First Century, Cambridge, 2012,  p. 20