Lead’s toxicity generates no end of health complications in the brain, up to and including encouraging dissociative and violent behavior. In the United States we began purging lead from our systems in the 1970s, systematically banning its use in product after product. Over the next half century, the ambient level of lead in our air dropped by more than 90 percent. At the same time, instances of violent crimes subsided from record highs to record lows. Correlation? Definitely. Causation? Let’s go with a strong maybe.*
