The papers linked in the article don't actually say that, and I'd like to see the papers that do - have you a link to them?
And is it so hard to think that the more progressive regions might do several things earlier than the less progressive regions? I'm not saying this is the actual mechanism at play, just that it's a plausible mechanism that is causal for both trends - something that's always overlooked in thees articles.
Anyway, I spent an hour looking at crime graphs for Australia this afternoon, and I can't see a common pattern at all. Australia banned leaded fuel in 1986 and it was completely phased out by 2000. But the crime graphs are all over the place. Homicide is stable-but-downward. Assualts are rising. Robbery has been both up and down. If lead is the 'silver bullet' against violent crime 20 years later, why the increase in assaults? I just don't see the preliminary patterns required for this "causation" to work.
The 60s and 70s were a time of massive social upheaval, and people came out of it with a better understanding of how to see other people by merit rather than by tradition. The "Think of the Children!" political slogan rose to prominence in the 70s. This is also the time of better rights for minorities, first wave feminism, and the rise of the phenomenon of questioning authority. Kids raised under the hippy ethos (and related) were far more common than in the 50s. The environments they grew up in had more equality and diversity measures from the civil rights movements. Not perfect, but certainly significant change.
And is it so hard to think that the more progressive regions might do several things earlier than the less progressive regions? I'm not saying this is the actual mechanism at play, just that it's a plausible mechanism that is causal for both trends - something that's always overlooked in thees articles.
Anyway, I spent an hour looking at crime graphs for Australia this afternoon, and I can't see a common pattern at all. Australia banned leaded fuel in 1986 and it was completely phased out by 2000. But the crime graphs are all over the place. Homicide is stable-but-downward. Assualts are rising. Robbery has been both up and down. If lead is the 'silver bullet' against violent crime 20 years later, why the increase in assaults? I just don't see the preliminary patterns required for this "causation" to work.
http://www.aic.gov.au/statistics.html