Half of Americans’ IQ scores Shrank Due to Lead Exposure

A new study suggests that half of Americans alive today may have had their IQ lowered due to lead exposure. The study looks at anyone born before the 1996 ban on leaded gasoline. Those born prior may have had their IQ lowered by three points on average. Exposed people may also suffer from faster aging of the brain as they age.

Pollution effects IQ in many other ways as well. The second half of the 20th century has had many influences on IQ development. Many scholars believe the drop in the crime rate in the late 80s may have been at least partially due to various laws reducing lead exposure. However, many people are still exposed. Especially in poor, often historically black communities. Communities where there’s no money to improve rotting public infrastructure. For instance, in Flint, Michigan.