This isn't the first time a study has suggested that lead exposure can lead to poor social outcomes. Since the early 2000s, economist Rick Nevin and Oxford physiologist Bernard Gesch have postulated that the decline in crime in many western nations—including the United States—since the late 1990s is correlated with the removal of lead from gasoline, because lead reduces the parts of the brain responsible for decision making and impulse control. It's not just that lead makes us dumber, they argue: it leads to terrible decision making. And by most measures, committing a crime is a bad decision. It's important to stress that their work is correlative—given what we know, conducting an experiment where we exposed children to lead and then watched to see if they later turned to a life of crime would be, well, criminal. But along with studies like Reuben's, the correlation is certainly thought-provoking.