"nobody is saying lead causes violent crime... many studies seems to show that it is a contributor to crime." This seems contradictory. How can it not cause v

"nobody is saying lead causes violent crime... many studies seems to show that it is a contributor to crime." This seems contradictory. How can it not cause violent crime yet be a causative factor? I can see how it might be correlated. But I've never heard a compelling argument for how it would be causative.on any significant level.