> Lead reduction probably resulted in a general increase of +5 IQ
I assume that this doesn't apply to the older generations alive today, so at what point do we reap the benefits of that across the political leadership?
We already have reaped the benefit with crime. There's very good evidence that phasing out of TEL was a major factor in the drop in crime starting in the 1990's. At that time, people who had been exposed to lead began to age out of crime.
Lead has an especially bad effect on executive function and impulse control, so I wouldn't be suprised if it had an effect on the behavior of voters in the aggregate and even politicians.
I assume that this doesn't apply to the older generations alive today, so at what point do we reap the benefits of that across the political leadership?