Lead Leads to Crime?

It appears to have a strong correlation.

Over the weekend, the Washington Post published an article suggesting that much of the decline in crime in the 1990s may have been due to the reduction of childhood lead exposure after the removal of lead from gasoline and house paint. This is an intriguing hypothesis. There is evidence on an individual level that high exposure to lead is harmful to both IQ and the ability to delay gratification, two traits that could enhance the attractiveness of crime. There is also some suggestive time-series evidence of a relationship: the rise and fall in lead exposure at the national level match the rise and fall in crime.