I don't think my little take on the lead-crime link gets enough attention. If we believe that the crime boom was due to lead exposure, then we also need to consider the impact that lead had on a range of asshole behavior that didn't show up in crime statistics.
Lead made people violence-prone assholes, but not all violence-prone assholes are convicted criminals. They're just violence-prone assholes we have to deal with in our daily lives. Some of them are probably in charge of important things.