Research Links Lead Exposure, Criminal Activity - washingtonpost.com - read entire article
From the article:
A recently released study concludes that there is a strong association between preschoolers' blood lead levels and crime rates 19 years later, when the preschoolers grow up. Declines in lead levels in several industrialized countries corresponded with later drops in crime rates, the study says.
Everyone should read this article. You have to register for the Washington Post online, but it is free. Do not allow leaded products around your child and they are still found in the USA.
A search for lead additive on Google today (7/8/07) was rewarded with 10+ page of results.