Is IQ really quantifiable and measurable and is it comparable across different people, different geographies and races? I didn’t think it was, may be I am wrong. How is IQ even defined?
Lead exposure in last century shrunk IQ scores of half of Americans: study
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Re: Lead exposure in last century shrunk IQ scores of half of Americans: study
#412Earlier quoted context omitted.
They didn't: https://commons.m.wikimedia.org/wiki/File:Homicide_Rate_in_N... https://www.japantimes.co.jp/news/2016/01/14/national/crime-...
The Nordic countries[1] all peak around '86-'92. Homicide is down world-wide since 1990[2]. This is a weird argument to make. I've never even encountered anyone who disagreed with this who has even a passing familiarity with criminology, economics, or broad societal trends. I'm not even sure what you're actually arguing here. You're coming across like a contrarian who is frantically googling for a counter point. Crim…
The problem is there is no evidence for any crime boom unless you pick the right location and the right beginning year (typically the post war years) or some such contrieved scenario. Even the graph in your second link shows it was completely insignificant.
Re: Lead exposure in last century shrunk IQ scores of half of Americans: study
#413Not only boomers got exposed to lead, they also got exposed to dioxin from trash burning, asbestos from construction, and who knows what else.
Re: Lead exposure in last century shrunk IQ scores of half of Americans: study
#414Black children had an adjusted 0.73 to 1.41 µg/dL more blood Pb (p https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7084658/
Learned about this phenomenon when considering buying a home built prior to 1978. The highest blood lead levels are seen in children living in denser population areas at or below poverty thresholds. Homes in these largely urban, low-income areas are disproportionately built before 1978 and subject inhabiting children to a significantly higher lead exposure risk. In 2014, it was estimated that 90 percent of all DC hom…
The issue is similar to the asbestos mania. Lead paint is a problem for young children mostly when it peels and gets ingested, or pulverizes and ends up in the air.
Because the strategy is elimination, lead remediation is a huge expense and has driven landlord behavior to embrace incredulous ignorance. There’s actually an incentive to not maintain property in some cases - remediation may exceed the value of the property.
A smarter strategy imo would be to reduce harm. Do stuff like pay landlords to replace windows and paint trim to encapsulate older lead paint. In poor neighborhoods, you could use this to incentivize section 8 enrollment which gives the government more power to drive other remedies for different problems.
I grew up in an 1890s home and live in a circa 1918 home today. There is almost certainly lead present in both the water supply lines and in various painted structures. Because the homes were/are maintained and the water system isn’t run by criminally negligent people, my kids do not have any lead exposure.
Re: Lead exposure in last century shrunk IQ scores of half of Americans: study
#415Re: Lead exposure in last century shrunk IQ scores of half of Americans: study
#416Earlier quoted context omitted.
The Nordic countries[1] all peak around '86-'92. Homicide is down world-wide since 1990[2]. This is a weird argument to make. I've never even encountered anyone who disagreed with this who has even a passing familiarity with criminology, economics, or broad societal trends. I'm not even sure what you're actually arguing here. You're coming across like a contrarian who is frantically googling for a counter point. Crim…
The problem is there is no evidence for any crime boom unless you pick the right location and the right beginning year (typically the post war years) or some such contrieved scenario. Even the graph in your second link shows it was completely insignificant.
The whole discussion is about the post war period. But if you look back further, homicide rates where higher. Again I’m not aware of any scholar, police organization, or or anyone really who disputes this. What even are you arguing here?
Re: Lead exposure in last century shrunk IQ scores of half of Americans: study
#417Earlier quoted context omitted.
There's also https://en.wikipedia.org/wiki/Titanium_dioxide#Possible_carc... , which is used in many glazes and coatings, but also as a whitener in health supplements and toothpaste!
Titanium dioxide is also widely used in cosmetics because it blocks ultraviolet light. Together with zinc oxide, it's the basis of sunscreen. As a pigment, titanium dioxide also seems like it's currently the go-to less toxic replacement for the lead-based pigments in lead paint.
Is it absorbed through skin pores when we put on sunscreen??
Re: Lead exposure in last century shrunk IQ scores of half of Americans: study
#418One of the most heartbreaking things I ever learned about was the high levels of lead in Mexican candy. This is apparently mostly due to the inks used in the packaging. https://annalsofglobalhealth.org/articles/10.5334/aogh.2754/ The following paper also pegs pottery as an issue. Just devastating. https://www.sciencedirect.com/science/article/pii/S221499961... > Our results indicate that more than 15% of the populati…
Ate so much Lucas powder growing up :(
Re: Lead exposure in last century shrunk IQ scores of half of Americans: study
#419Is IQ really quantifiable and measurable and is it comparable across different people, different geographies and races? I didn’t think it was, may be I am wrong. How is IQ even defined?
There is a great Radiolab series about this: G. The IQ test is an effort to measure "general intelligence", or "G", but the test has had biases over time with regard to race.
The landmark study by Herb Needleman on the link between lead exposure and IQ only studied white children to reduce any doubts about the validity of its claims [1].
[1] https://www.wnycstudios.org/podcasts/radiolab/articles/g-pro...
Re: Lead exposure in last century shrunk IQ scores of half of Americans: study
#420Didn't we have a previous study debunking this research on statistical grounds?
What has never made sense to me is that the IQ effects aren't equally visible across income/class groups, but we know there are millions of wealthy people living in old housing in Boston and NYC and Providence and so on. Lead levels in those houses must be just as high, right? But those kids aren't experiencing the same IQ effects. Surely this suggests that something else is a bigger factor?
It's only 3 IQ points, 1/5 of a standard deviation so not really massive. Of course there are much bigger effects on IQ such as the factors that cause low income children, and people in poor countries to have low IQs which swamp the lead effect.