Enlightenment now

I think Steven Pinker's book The Better Angels of our Nature was a fantastic book and I am very curious about his new book Enlightenment now. The book argues that, while many people are pessimistic, the world is actually getting better in countless ways. The book also argues for Enlightenment values such as reason and humanity. While I am all for Enlightenment values, I am curious how convincingly Pinker shows the causal relation between the adoption of Enlightenment values and progress. So far, I have mainly heard him argue that there is much progress. I have not heard him explain clearly that this progress is caused by Enlightenment values.