This won't come as big news to readers of this blog, but it's worth posting just for the headline alone:
A new study calculates that exposure to car exhaust from leaded gas during childhood stole a collective 824 million IQ points from more than 170 million Americans alive today, about half the population of the United States.
....The researchers calculated that at its worst, people born in the mid-to-late 1960s may have lost up to six IQ points, and children registering the highest levels of lead in their blood, eight times the current minimum level to initiate clinical concern, fared even worse, potentially losing more than seven IQ points on average.
Dropping a few IQ points may seem negligible, but the authors note that these changes are dramatic enough to potentially shift people with below-average cognitive ability (IQ score less than 85) to being classified as having an intellectual disability (IQ score below 70).
The effect of lead on violent crime is a relatively new finding and it's still controversial. The effect of lead on IQ isn't. It's one of the oldest and most widely accepted findings in the literature. There's not much question that leaded gasoline reduced human intelligence worldwide among those born around 1960-1990 or so.
And the researchers are right about the effect, which is similar to the effect on violent crime. For those in the average IQ zone (or the average violence zone) the loss of a few points of IQ isn't that big deal. But the effect of lead is at its peak in poor communities and urban cores, where more people already have below-average IQ and above-average propensities for violence. A difference of six points is the difference between, say, average IQs of 90 and 84. Or, even worse, between average IQs of 80 and 74, with similar levels of change in violent behavior. Those are gigantic differences.
POSTSCRIPT: In a stunning abuse of significant digits, the authors of the paper actually estimated a loss of 824,097,690 IQ points. Uh huh.
A difference of six points is the difference between, say, average IQs of 190 and 184. Or, even worse, between average IQs of 180 and 174, with similar levels of change in violent behavior.
Am I missing something, or would those IQ scores indicate something like Einstein-level genius?
That's way above Einstein. That's Charly Gordon level genius.
Well, at his peak.
Einstein was not considered by his colleagues to be super intelligent but rather an exceptionally creative intellect capable of making nonlinear creative jumps that evaded everyone else. Enrico Fermi was widely considered to the smartest physicist in terms of conventional intellect.
it's been fixed now...
Two comments:
(1) I think there is a sort of a type, but really a 'thinko' where Kevin was thinking one thing and typed another. In the last paragraph, in the explanation of the significance of a six point difference, Kevin contrasts an IQ of 190 vs 184, or 180 vs 174. I doubt that's what he meant; I think those leading ones crept into the sentence.
(2) There is an insidious statistical malapropism in the construct. If the IQ penalty was 6 points, that does NOT mean all the exposed kids lost 6 points each. The loss was distributed statistically, with a mean value of 6. What was the standard deviation of that statistic? Who knows, but it would not be at all surprising to discover that the standard deviation was also about 3 or 4. That would mean that 1/6 of the kids suffered little or no loss, while 1/6 of them suffered a loss of 9-10 points (or more).
It's the kids at the negative tail of the distribution who become violent offenders. And with that distribution over many millions of affected individuals, that's a LOT of violent offenders we created.
There is no "distribution" - this is not the results of IQ measurement, just a hypothetical calculation of what the effects of lead might be, assuming somebody's relationship between lead exposure and IQ.
Unless the dose-response curve is a step function, there would be a distribution. The phrases “up to six IQ points”, “seven IQ points on average” are clearly allusions to a distribution of values.
In regards to the postscript, we can probably chalk up the error to some of those lost IQ points. 😛
Especially when one watches Faux News for a few minutes, no?
Tucker Carlson: born 16 May 1969.
That could explain the rise (and cognitive decline) of the Republican Party as these lead-exposed kids attained voting age.
hmmm...lead exposure vs. party ID.....you might be on to something!
Careful there. Republicans tend to live in more rural areas, with lower traffic density and thus lower lead levels from gasoline. The lead exposure vs. party ID correlation might not be what you hoped.
The possible effect on law enforcement officers who are often required to spend time at indoor target ranges with high levels of lead vapor is troubling.
& we know they go unmasked!
I thought IQ was supposed to be a disparaged measure of intelligence?
Stop reading only progressive blogs and "Stopped Clock Is Right Twice A Day" Black Swan man.
It's a reproducible psychometric and it's one of the only ones. We can argue over what or how much it measures, but it correlates to lots of good things in people's lives (and some bad). Whether there is a cause/correlation with certain "western" things is not the point.
It's as real as these things get. Whether or how much it is genetic and whether or how much genes have anything to do with "race" is an entirely separate issue and doesn't bear on this.
Explain now why 'intelligence' is 'equated to lots of good things'. Show your work. God, how the uniformed do love to opinionate on matters they know nothing about.
Here: https://www.jstor.org/stable/23093686
Sternberg does a careful review; he does however have his own theory of intelligence, which attempts to respond to some of the criticisms of IQ testing.
Paywalled.
Hmm. I was offered 100 free reads per month as an independent researcher.
Got it, thanks. Had to login with my university id and email, so entirely appropriate to this conversation ... duh.
Scent, why did you put quotation marks around your own choice of words that was NOT the phrase you were misquoting.
The phrase you misquoted was NOT “equated to…” Rather, it was “correlates to…”, which is clearly and indisputably correct.
Well, two things here: a) single quotes -- tics -- can be used to indicate paraphrases, and b) you're still wrong, because I'm asking how _intelligence_ is equated with 'lots of good things.'
If you want to argue that it is, well, _I'm_ not forcing you to do so. But if you are, well, it's an amazingly stupid argument.
How then did the authors control for the shortcomings of the measure?
No. Yet another edition of simple answers to stupid questions.
It appears as though we got the lead out of paint and gasoline a whole lot faster than KD can get the anti-semitic lead(Spades) out of his blog
THAT move would certainly raise the IQ here
+1
Now where did I put my marbles....anyone seen them?
Keep in mind that IQ is scaled (usually within country I believe) so that the mean IQ is 100 and the standard deviation is 15. If half the country would have had, on average "6 more IQ points", both the mean and the SD would have remained the same, by design, but the meaning of each value of IQ, and the real difference (i.e., pre-scaling) between 2 different values of IQ would have been somewhat different.
This is without even getting into the Flynn Effect.
https://en.wikipedia.org/wiki/Flynn_effect
Besides the abuse of significant digits, there is the entirely meaningless summation of ‘lost IQ points’ over a subpopulation. This is like noting that 100 reporting stations around a state each noted a 10C increase in temperature today over yesterday, therefore the state was 1000C hotter!
Santana & Rob Thomas tried to warn us...
"In a stunning abuse of significant digits, the authors of the paper actually estimated a loss of 824,097,690 IQ points."
Well, that's what the calculator said.
Lead --> crime : Kevin Drum :: Naked Pictures of famous people : Jon Stewart.
Those were their absolute peaks as cultural totems, & it's been a sad & maddening, respectively, descent for both in the last decade or so. But not sure if it's worse that Obama actually winning in 2008 broke Stewart irrevocably, or that Elizabeth Warren losing in the 2020 Democrat primary broke Drum. (Let's call it a tie.)
I'm adding this to my cocktail party argument that everything is getting better because we've gotten the lead out! Crime is going down and people are getting smarter! Bye bye GOP!