Part 1: What human genetics of lipids and psychiatric disease teach us about the answer to: What fraction of causal human biology do we actually know? I have been asking a version of this question for months now – at lunch, over dinner, on walks with friends and colleagues. For fun, I have gotten into the habit of politely pressuring people for a single number. Come on, just give me your best guess! Almost without exception, as we worked through the answers together, we did not land on a single number. Instead, we debated a structure. This blog is an...