Sunday, November 11, 2007

DNA and New Fears of Prejudice

The New York Times has a very interesting article about how new DNA tools may be reinforcing prejudice--particulalry since many geneology DNA programs seem to reinforce cultural concepts of race into DNA family groups:


When scientists first decoded the human genome in 2000, they were quick to portray it as proof of humankind’s remarkable similarity. The DNA of any two people, they emphasized, is at least 99 percent identical.

But new research is exploring the remaining fraction to explain differences between people of different continental origins.

Scientists, for instance, have recently identified small changes in DNA that account for the pale skin of Europeans, the tendency of Asians to sweat less and West Africans’ resistance to certain diseases.

At the same time, genetic information is slipping out of the laboratory and into everyday life, carrying with it the inescapable message that people of different races have different DNA. Ancestry tests tell customers what percentage of their genes are from Asia, Europe, Africa and the Americas. The heart-disease drug BiDil is marketed exclusively to African-Americans, who seem genetically predisposed to respond to it. Jews are offered prenatal tests for genetic disorders rarely found in other ethnic groups.

Such developments are providing some of the first tangible benefits of the genetic revolution. Yet some social critics fear they may also be giving long-discredited racial prejudices a new potency. The notion that race is more than skin deep, they fear, could undermine principles of equal treatment and opportunity that have relied on the presumption that we are all fundamentally equal.

“We are living through an era of the ascendance of biology, and we have to be very careful,” said Henry Louis Gates Jr., director of the W. E. B. Du Bois Institute for African and African American Research at Harvard University. “We will all be walking a fine line between using biology and allowing it to be abused.”

Certain superficial traits like skin pigmentation have long been presumed to be genetic. But the ability to pinpoint their DNA source makes the link between genes and race more palpable. And on mainstream blogs, in college classrooms and among the growing community of ancestry test-takers, it is prompting the question of whether more profound differences may also be attributed to DNA.

. . .

Though few of the bits of human genetic code that vary between individuals have yet to be tied to physical or behavioral traits, scientists have found that roughly 10 percent of them are more common in certain continental groups and can be used to distinguish people of different races. They say that studying the differences, which arose during the tens of thousands of years that human populations evolved on separate continents after their ancestors dispersed from humanity’s birthplace in East Africa, is crucial to mapping the genetic basis for disease.

But many geneticists, wary of fueling discrimination and worried that speaking openly about race could endanger support for their research, are loath to discuss the social implications of their findings. Still, some acknowledge that as their data and methods are extended to nonmedical traits, the field is at what one leading researcher recently called “a very delicate time, and a dangerous time.”

“There are clear differences between people of different continental ancestries,” said Marcus W. Feldman, a professor of biological sciences at Stanford University. “It’s not there yet for things like I.Q., but I can see it coming. And it has the potential to spark a new era of racism if we do not start explaining it better.”

Dr. Feldman said any finding on intelligence was likely to be exceedingly hard to pin down. But given that some may emerge, he said he wanted to create “ready response teams” of geneticists to put such socially fraught discoveries in perspective.

. . .

“I’ve spent the last 10 years of my life researching how much genetic variability there is between populations,” said Dr. David Altshuler, director of the Program in Medical and Population Genetics at the Broad Institute in Cambridge, Mass. “But living in America, it is so clear that the economic and social and educational differences have so much more influence than genes. People just somehow fixate on genetics, even if the influence is very small.”



The problem is that nonscientists, through bloggs and the like, are misunderstanding--or at the very least misstating the genetic evidence for racial differences:

Nonscientists are already beginning to stitch together highly speculative conclusions about the historically charged subject of race and intelligence from the new biological data. Last month, a blogger in Manhattan described a recently published study that linked several snippets of DNA to high I.Q. An online genetic database used by medical researchers, he told readers, showed that two of the snippets were found more often in Europeans and Asians than in Africans.

No matter that the link between I.Q. and those particular bits of DNA was unconfirmed, or that other high I.Q. snippets are more common in Africans, or that hundreds or thousands of others may also affect intelligence, or that their combined influence might be dwarfed by environmental factors. Just the existence of such genetic differences between races, proclaimed the author of the Half Sigma blog, a 40-year-old software developer, means “the egalitarian theory,” that all races are equal, “is proven false.”

. . .

The authority that DNA has earned through its use in freeing falsely convicted inmates, preventing disease and reconstructing family ties leads people to wrongly elevate genetics over other explanations for differences between groups.

“I’ve spent the last 10 years of my life researching how much genetic variability there is between populations,” said Dr. David Altshuler, director of the Program in Medical and Population Genetics at the Broad Institute in Cambridge, Mass. “But living in America, it is so clear that the economic and social and educational differences have so much more influence than genes. People just somehow fixate on genetics, even if the influence is very small.”

But on the Half Sigma blog and elsewhere, the conversation is already flashing forward to what might happen if genetically encoded racial differences in socially desirable — or undesirable — traits are identified.



Read it all here.

By the way, there is very interesting work on the so-called "intelligence gap" dexcribed on the Freakonomics blog, which shows that there are no racial differences in mental functioning at age one, although a racial gap begins to emerge over the next few years of life. This seems to support a theory that cultural and environmental influences, rather than genetics, most strongly influsnce outcomes like intelligence.

1 comment:

Anonymous said...

The test on 1 year olds referenced over at Freakanomics was based on a shortened version of the Bayley Scale of Infant Development.

The test does a pretty good job of predicting mental retardation, but a very poor job of predicting IQ, at least until the age of 4.

Sigelmann, C.K. & Rider, E.A. (2005). Life-span Human Development. New York: Wadsworth.

link (p. 232

This might explain why the freakonomics paper still hasn't been approved for review.