Is that a result of lead or the policies created in the 1970s that helped cause a massive increase in single-parent homes among those in poverty? There are a lot of factors that contributed to that crime wave. The Great Society started by Johnson and expanded by Nixon likely has had a far bigger effect than simply lead. It’s an area of study though that is plagued by politics and stifled by political correctness. It’s much easier to simply blame it on lead. But considering that lead was around in unhealthy levels long before that generation entered adulthood, one must look at what changed in the socio-welfare-cultural structure preceding that “massive crime wave.” But, to do that would call into question a generation of social policy which is very uncomfortable for many.

It fairly closely tracked both lead exposure in both time frame and location. So, while no single factor was completely responsible lead had a major impact.