Global smarts. In this map, countries shaded purple have the highest average IQ. Those shaded dark red have the lowest IQ—and, typically, the highest incidence of infectious disease.
Credit: Wikimedia Commons
Posted on 07/01/2010 8:55:14 PM PDT by neverdem
What can you do to make your kids smarter? Keeping them healthy might help. A new study suggests that worldwide differences in intelligence can be explained by disparities in infectious disease. The researchers found that countries most heavily affected by infectious diseases generally had the lowest average IQs. They propose that these illnesses hinder children's brain development, though their conclusion is gathering mixed reviews.
The new research relies on data first published in 2002 in a controversial book called IQ and the Wealth of Nations. In the book, psychologist Richard Lynn of the University of Ulster in the United Kingdom and political scientist Tatu Vanhanen of the University of Tampere in Finland searched the published literature to come up with measures of average IQ for 81 countries. They also estimated IQ for another 104 countries by averaging the IQs of nearby nations. Hong Kong topped the list, with an average IQ of 107. The authors argued that national differences in IQ at least partly explained differences in national wealth. In 2006, they expanded the data to include IQ measurements from 113 countries and new estimates for 79 more.
Several groups have attempted to explain the pattern. In the new study, Christopher Eppig, a Ph.D. candidate in biology at the University of New Mexico, Albuquerque, and his colleagues propose that low IQ is tied to the toll of infectious diseases. Their idea, which the researchers call the "parasite-stress hypothesis," is that children who contract "parasites," which they define to include everything from intestinal worms to bacteria and viruses, devote more energy to fighting off infection. As a result, they have less energy available for brain development. Countries where infectious diseases are prevalent, Eppig and colleagues argue, will have lower intelligence.
To test this idea, the researchers statistically analyzed the relationship between Lynn and Vanhanen's 2006 data and 2004 data on infectious disease burden from the World Health Organization, which measures potential years of healthy life lost to premature death and illness as a result of 28 infectious diseases, including malaria, hepatitis, and tetanus. The researchers also reexamined factors that other research groups had linked to IQ, such as nutrition, literacy, education, gross domestic product, and temperature.
The numbers seem to support the hypothesis, the team will report online tomorrow in the Proceedings of the Royal Society B. When the researchers analyzed each factor independently, they found that infectious disease burden was more closely correlated to average IQ than the other variables. "Parasites alone account for 67% of the worldwide variation in intelligence," Eppig says. To further assess the relationship, the researchers built a statistical model that allowed them to test the predictive power of infectious disease burden against other variables previously associated with IQ, such as education, temperature, distance from sub-Saharan Africa, and wealth. Infectious disease burden again came out on top, although temperature and distance from sub-Saharan Africa explained some of the variation as well.
Eppig points out that their study can't rule out any of the other factors. "I would never say that parasites are the only thing affecting the global diversity of intelligence."
Maureen Black, a pediatric psychologist at the University of Maryland School of Medicine in Baltimore, is skeptical. She argues that health by itself isn't enough for full brain development. "For children to develop intellectual skills, they need not only strong bodies and the absence of infections, they also need opportunities to explore and opportunities for enrichment." Those opportunities might be lacking in countries with low average IQ.
But Richard Guerrant, a physician and infectious disease expert at the University of Virginia School of Medicine in Charlottesville, says the researchers are on the right track. His work suggests a link between diarrheal diseases, malnutrition, stunted growth, and lower IQs. The next challenge, he says, will be to uncover the exact mechanisms.
Oopsie - fail in geography. Must be worms.
China then.
“Do Parasites Make You Dumber?”
Surely they must. The plague in DC is a stark reminder of the ongoing crisis associated with these parasites.
They make me poorer by virtue of their lack of compulsion to pay taxes.
Too many variables to be testable.
Too many variables to be testable.
A fine book.
As for the study, it is a bit too politically correct to take at face value.
You mean like Zombies?(click the pic)
How could you know? IMHO, our ability to intuitively correlate, often with very imperfect knowledge, is what makes us great guessers. I think most human correlations (where there is smoke, there is fire) are likely to be correct. However, we also need to be humble and we need to try to begin to understand our limitations and our tendencies toward hubris and self-deceit.
Highly simplified bayesian analysis. The universe of causal relationships is a subset of the universe of predictive relationships. The universe of predictive relationship (correlations) tends towards infinity. The universe of causal relationships is finite. Thus the likelihood that a predictive relationship is also a causal one is rather small and most correlations therefore are *probably* non-causal. Think of it as a Venn diagram where casual relationships are a tiny circle inside a much much larger circle of predictive relationships. Randomly throwing darts at the circle, you're much more likely to land outside the inner circle than inside it.
How about the colder the temp(or harsher the enviornment) the folks had to be smarter to survive and so evolved.
If you listen to their leftist drivel; yes.
Uh huh. Anything to justify the "progressive" agenda - truth is no object.
lmao!
On Futurama they make you super smart ;)
But this involves discussing nature rather than nurture, and that mustn't be.
They would find a higher association if they just looked at world temps vs IQ. There is a very high correlation just looking at the map.
micro ping
I do think the weather has something to do with it...at least it did originally when people had to survive by their wits.
Do liberals eat less red meat? Could diet cause that particular disorder?
I know, I know.
I’m sorry to hear about your friend. I’ve never heard of babesiosis before. Sounds horrible.
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