June 16, 2006

Diversity Trumps Scientific Inquiry in the Land of the Free and the Home of the Brave, Part 426

Bruce Lahn's discovery last fall of two genes apparently related to brain development that have been under recent selection was quantitatively overwhelmed by Bob Moyzis's HapMap analysis last December of 1,800 genes, no doubt hundreds of which are related to cognition, that have been under different selection pressures on different continents over the last 50,000 years. Nicholas Wade of the New York Times didn't have a chance to cover Moyzis's paper when it came out, so much of the attention remains on Lahn's earlier work.

I talked to this WSJ reporter for about an hour six weeks ago when he was researching this article, as I mentioned in my review of Nicholas Wade's Before the Dawn.

From the front page of today's Wall Street Journal:


Head Examined: Scientist's Study Of Brain Genes Sparks a Backlash

Dr. Lahn Connects Evolution In Some Groups to IQ; Debate on Race and DNA 'Speculating Is Dangerous' By ANTONIO REGALADO June 16, 2006; Page A1

CHICAGO -- Last September, Bruce Lahn, a professor of human genetics at the University of Chicago, stood before a packed lecture hall and reported the results of a new DNA analysis: He had found signs of recent evolution in the brains of some people, but not of others.

It was a triumphant moment for the young scientist. He was up for tenure and his research was being featured in back-to-back articles in the country's most prestigious science journal. Yet today, Dr. Lahn says he is moving away from the research. "It's getting too controversial," he says.

Dr. Lahn had touched a raw nerve in science: race and intelligence....

Dr. Lahn has drawn sharp fire from other leading genetics researchers. They say the genetic differences he found may not signify any recent evolution -- and even if they do, it is too big a leap to suggest any link to intelligence. "This is not the place you want to report a weak association that might or might not stand up," says Francis Collins, director of the genome program at the National Institutes of Health....

Pilar Ossorio, a professor of law and medical ethics at the University of Wisconsin, criticizes Dr. Lahn for implying a conclusion similar to "The Bell Curve," a controversial 1994 bestseller by Richard J. Herrnstein and Charles Murray. The book argued that the lower average performance by African-Americans on IQ tests had a genetic component and wasn't solely the result of social factors. Referring to Dr. Lahn and his co-authors, Prof. Ossorio says: "It's exactly what they were getting at. There was a lot of hallway talk. People said he's doing damage to the whole field of genetics."

The 37-year-old Dr. Lahn says his research papers, published in Science last September, offered no view on race and intelligence. He personally believes it is possible that some populations will have more advantageous intelligence genes than others. And he thinks that "society will have to grapple with some very difficult facts" as scientific data accumulate. Yet Dr. Lahn, who left China after participating in prodemocracy protests, says intellectual "police" in the U.S. make such questions difficult to pursue...

Henry Harpending, a University of Utah anthropology professor who recently published a theory for why Ashkenazi Jews tend to have high IQ's, says Dr. Lahn once suggested they co-author an article for Scientific American about the genetics of behavior, in which they could explain why "Chinese are boring."

"I think that Bruce doesn't understand political correctness," Dr. Harpending says. Dr. Lahn says he only vaguely recalls the conversation but confirms that he wonders whether during China's imperial times there was "some selection" against rebellious individuals.

In recent years, Dr. Lahn has become interested in why the human brain is so large and complex. Although humans and chimpanzees share about 96% of their DNA, human brains are about four times larger. Even today, researchers can find a correlation, on average, between people's brain size and their IQ...

"You have to follow the data wherever it leads, but speculating in this field is dangerous," says Spencer Wells, head of the National Geographic Society's Genographic Project, a five-year, $40 million effort to collect DNA samples from 100,000 indigenous people. Dr. Wells says the project team might try to find evolutionary reasons for physical differences such as why Danes are taller than pygmies. But Dr. Wells says National Geographic won't study the brain. "I think there is very little evidence of IQ differences between races," he says...

Dr. Lahn stands by his work but says that because of the controversy he is moving into other projects. Earlier this year, Mr. Easton of the university's media department forwarded Dr. Lahn a paper by two economists looking at the IQ of infants of different races. Dr. Lahn wasn't interested. "I'm surprised anyone studies this," he replied in an email. [More]


By the way, the two economists are undoubtedly Steven D. "Freakonomics" Levitt and Roland G. Fryer and the paper is one where they showed that a test of infant liveliness (e.g., how often the infant babbles) that has a low but positive correlation with childhood IQ doesn't show the normal differences between the races at age 8 to 12 months. Indeed, the highest IQ children (Northeast Asians) do the worst on this test of infant vivacity. With a typical Freakonomic leap of faith, Levitt and Fryer suggested that this shows that IQ differences aren't genetic but are caused by environmental differences, presumably between age 1 and the earliest ages at which IQ tests are semi-reliable.

Of course, all Levitt actually did was show that this test of infant liveliness was a racially biased predictor of IQ. Why is it racially biased? Well, there are lots more ways for something to go wrong than to go right, but one obvious possibility is that the test of infant alertness might measure traits that differ on average between the races, but aren't related to IQ differences between the races. For example, within a race, babies that babble more turn out to be a little bit smarter on average than more taciturn babies. Yet, Asian infants don't babble as much on average as other babies, but that doesn't mean they'll turn out to have lower IQs on average than babies from races that babble more. But pointing out that this test of babies is racially biased is not as sexy a story as claiming it shows Nurture Triumphs Over Nature.


My published articles are archived at iSteve.com -- Steve Sailer

No comments: