Chart of the Day: Fewer People Are Being Sent to Prison. Way Fewer. | Mother Jones: Here's some further data from Rick Nevin:
From 2002 to 2012, the incarceration rate fell 51% for men ages 18-19, 30% for men ages 20-24, and 21% for men ages 25-29....The prison population has fallen at a slower rate because steep incarceration declines for young men have been offset by rising incarceration for older adults. From 2007 to 2012, the incarceration rate increased by 21% for men ages 45-49 and surged 45% for men ages 50-64.
Incarceration rates are way down for men in their teens and 20s, who grew up in the relatively lead-free post-1990 environment. But for older men, who grew up before then, incarceration rates are actually up. Lead did its work on them long ago.