Efforts to reduce lead exposure in the 1980s arguably were behind much of the lower crime rates in the 1990s and 2000's that we've seen. There are other studies

Efforts to reduce lead exposure in the 1980s arguably were behind much of the lower crime rates in the 1990s and 2000's that we've seen. There are other studies cited in relevant wikipedia articles like https://en.wikipedia.org/wiki/Crime_in_the_United_States#cite_note-13 https://en.wikipedia.org/wiki/Crime_in_the_United_States#cit... And yes, crime rates are significantly lower adjusting for population, though that's not always conveyed accurately by those in authority and the news media.