I was browsing the web last night and reading up on the huge rise in crime, including violent crime, in western countries between the 1940s and early 1990s and the subsequent sharp fall in crime rates since then. Both the rises and falls have been very dramatic. The rise-fall curve is particularly dramatic in the USA.
Many criminologists and sociologists have put forward numerous theories for the causes and factors in this trend. Increasing urbanisation, the after-effects of the liberal 1960s, social and racial inequalities, decline of organised religion, increase in drug use, changes in policing and incarceration rates, migration patterns within cities (i.e. "White flight" in the 1950-80 era) and so on.
But there is one startling correlation - that of lead in the environment, particularly in petrol (youngsters may not know that lead in petrol was the norm until the late 1980s) and crime rates. There appears to be a 20 year lag between environmental lead levels and crime rates. We now know that lead is a potent neurotoxin which alters and damages the human brain, especially that of babies and children. Indeed, many if not most posters on here over the age of 35 - me included - were probably exposed to too much lead in our environment.
Basically the lead-crime hypothesis asserts that children born when petrol lead was the norm were poisoned by this lead, leading to reduced intelligence and higher risks for criminal and violent behaviour. This would be especially marked in locations with high air lead pollution levels, such as major cities.
Conversely, since the phasing out of lead in petrol in the past 30 years, crime rates have fallen - sharply in places. All despite differing policing and sentencing regimes.
Now, I find this theory very interesting. Personally, I think the crime curve trend was caused by a multiplicity of factors but the lead pollution correlation is startling. Yes I know correlation does not mean causation, but it is very interesting all the same.
Which leads me to ponder what sort of other known pollutants/toxins in our environment- such as PCBs, female-mimicking hormones in pesticides, pthalates and so on - could be affecting human development and behaviour. We are being poisoned - but how is that playing out?
Link here:
https://youtu.be/SYUgGs9IStY