Wednesday, May 31, 2006

IQ and infant mortality

Lynn and Vanhanen spotlighted the relationship between IQ and the purchasing power parity of nations. It was a groundbreaking new way of understanding prosperity in the world. But PPP's relationship with IQ (contemporary correlation of .60) is actually weak in comparison to IQ's relationship to a host of other quantifiables (Economic transparency/corruption index: .68, Distance from the equator: .67, Births per woman: -.81, Life expectancy: .85). When economic transparency/corruption is taken into account, the effect of IQ on PPP completely disappears, while controlling for a host of variables (IQ, distance from the equator, births per woman, net migration rate, life expectancy, and economic freedom) only mildly moderates the effect of economic transparency/corruption while rendering all the other variables statistically insignificant except for the migration rate (positive net migration being correlated with higher PPP).

Another surprisingly strong correlation exists between IQ and the infant mortality rate. The two are inversely correlated at a statistically significant .84. Thus 70% of a country's infant mortatlity rate can be 'explained' by its average IQ. By way of comparison, PPP and infant mortality are inversely correlated at a more modest .56. Even doctors per capita and infant mortality are only inversely correlated at .69. Controlling for IQ renders PPP meaningless. Doctors per capita retains statistically significant but loses two-thirds of its correlation magnitude. Controlling for PPP and doctors per capita, meanwhile, only cuts into 21% of IQ's 'effect' on infant mortality. Boosting African IQs through better nutrition will do more for the well-being of the continent than the noble Doctors without Borders organization will ever be able to accomplish (maybe they should focus on distributing vitamins).

Why does IQ matter more than access to physicians or material well-being? There's plenty of food for speculation: Smarter women have more self-control to refrain from activities during pregnancy that may damage the fetus like smoking, eating junkfood, and consuming alcohol, they have fewer kids and have them later in life so they can devote more attention to each child without the distractions of youth, sharper couples are less likely to get divorced and therefore children benefit from having two caretakers instead of one, brighter couples have brighter children that are less likely to accidentally kill themselves, and smarter people are less given to instant gratification that distracts from properly caring for infants.

The future looks precarious. The brainy nations are becoming grayer and reproducing below the replenishment rate of 2.1 children per woman (see the nearby charts--click to enlarge).

Globalization will continue to make migration easier. As newly-arrived, formerly destitute third-worlders enjoy the prosperity of the developed host, they become more fecund (Hispanics in the US average 2.8 babies per woman. That's higher than Mexico's 2.42 per woman, and indeed is more fertile than much of Latin America). By depressing wages and making housing less affordable, they also have the effect of decreasing the fecundity of the host country's natives. As the relative size of the smart fraction dwindles while the duller side grows proportionately (and absolutely, of course), more human resources will have to spent by the brights to take care of the dulls. Crime and poverty will increase, living standards will be pressured, and human progression will be slowed.

Three ways to combat this: 1) Genetic engineering, the azoth that will potentially make all this worrying silly, 2) Technologies and techniques to slow down the aging process, keeping erudite old folks productive longer (SENS research is a worthy cause for charitable contributions), and 3) The creation of incentives for natives of the developed world to have more babies. France, Russia, and Portugal have recently implemented policies in attempt to achieve this. The US should give tax credits to high IQ professionals for donating sperm and eggs. The child tax credit should be regressive, or at least not progressive. Tubal ligations and other forms of sterilization should be used more by prosecutors as part of plea deals for criminals (Project Prevention is another worthy cause to consider).

(Future)

11 comments:

Kurt, Portland Oregon said...

Is there any published data on the corelation between IQ and religious belief?

Kurt, Portland Oregon said...

Never mind my previous question. A simple google search answered it.

crush41 said...

Religiosity has a powerfully negative inverse correlation with IQ. But that is mistakenly interpreted as revealing the bane of religion (there's plenty of facileness when it comes to analyzing religion and social outcomes). Lots of elitist like to superciliously snipe at religious folk (gleefully remarking how dumb and poor the religious are, but rarely mentioning that minorities in the US are more religious than whites).

Of course, being pious doesn't lower one's IQ. But less intelligent people are going to need more guidance/revelation to explain things they are unable to ascertain independently. What I would like to see is a study on the effect of religiosity once IQ is controlled for.

Dullards are better off being inculcated with Erasmus' Enchiridion than they are internalizing hip-hop or MTV cultural ethos.

tc said...

"As newly-arrived, formerly destitute third-worlders enjoy the prosperity of the developed host, they become more fecund (Hispanics in the US average 2.8 babies per woman. That's higher than Mexico's 2.42 per woman, and indeed is more fertile than much of Latin America)."

How do you know if they would be less fertile in Mexico? Maybe the subgroups of Mexicans who send immigrants are more fertile than Mexico's average.

JSBolton said...

Immigration from Mexico, and generally does not come from the poorer and most fecund percentiles, but from a more middling group.
With the economic transparency corruption index: this correlation would have to be discounted at least as much as you have discounted the IQ/income per capita one.
If we transfer most of the accountants from the richer to the poorer countries, and proportionally so, and back them up with armies more than in Iraq or Afghanistan, this will generate no rise in per capita income.
It would only facilitate taxation, if the average IQ's remain as before.

crush41 said...

TC,

Good point. It's informed speculation. Immigrants from Mexico tend to be better educated(eight years vs five years) and have the minimal resources required to make it north. Assuming typical fertility trends this would suggest that, as John said, Mexican migrants should be less fecund than the average Mexican native.

JSBolton,

But I think it does generate a rise in per capita income. Other things being equal, businesses invest and act in places where they are least likely to be plundered by government, subject to nationalization, or needing to pay bribes. Entrepreneurs and professionals find less corrupt places more amenable to enterprise. If these business people are coming to the developing or third world from developed countries, their spending will also have an effect on the receiving nation's PPP.

Singapore, Hong Kong, and the UAE are pretty clean business ports, and consequently they're wealthier than the nations surrounding them.

mping said...

Interesting post. I had noticed that countries appeared to be richer the farther away from the equator they are located, but I had never seen it quantified before. Thanks for that.

I am curious, the correlations that you state for Economic transparency/corruption, Distance from the equator, Births per woman, and Life expectancy, where did you get them? Was it from the book you mention, did you find them elsewhere, or did you calculate them yourself based on the sources you specify?

crush41 said...

mping,

I calculated it myself taking data from the sources I linked to. If you'd like, I'll send you the excel file with the correlation results and the data. Let me know.

undergroundman said...

I'm pretty sure you're confusing fertility and fecundity. Fecundity is a biological term related to the ability to reproduce.

None of your links support your assertions. (Perhaps update the links to the CIA World Factbook?)

What I would like to see is a study on the effect of religiosity once IQ is controlled for.

That's impossible.

Lots of elitist like to superciliously snipe at religious folk (gleefully remarking how dumb and poor the religious are, but rarely mentioning that minorities in the US are more religious than whites).

And that matters how? You may want to study the effect of wealth and education on religiosity. Minorities are paid less and clearly receive worse education.

crush41 said...

Underground,

I'm not sure what you're arguing.

Your understanding of the definition of the word fecundity is wrong. Here it is.

As for the theoretical study, it would be simple: Take a sample, see how they fare on IQ tests, probe for self-described religiosity, and run a couple of regressions. It wouldn't be difficult.

undergroundman said...

Fecundity: the quality of being fecund; capacity, esp. in female animals, of producing young in great numbers.

Capacity. It's not really meant to be a fancy word for fertility. When describing birth rates fertility works just fine. :)

http://en.wikipedia.org/wiki/Fecundity
http://en.wikipedia.org/wiki/Fertility

Take a sample, see how they fare on IQ tests, probe for self-described religiosity, and run a couple of regressions.

I was thinking you wanted to test the effect of religiosity on IQ, which doesn't even seem like it would have a causal relationship. Low IQ --> religiosity, no? Even if it does cause someone to be dumber, you couldn't discover that cause with statistics, heh.

How would the test you describe accomplish anything different than the scatter plot you linked to? (Which, by the way, is working with country IQ and country religiosity, as I'm sure you are aware.)