This podcast covers a bunch of it: https://www.youtube.com/watch?v=S5nj3DLvT64

It's one of those things that can be tricky to research because almost all the researchers and journalists on the topic very much don't want to see this conclusion. So there's a tremendous amount of misrepresentation and wishful reasoning about how to interpret the data. The truth comes out from actually reading the data, not researcher or journalist summaries.