AS THE 20th-century world recoiled from the horrors of Nazi Germany and the eugenics movement, we learned how economic, political and social circumstances produced the racial differences that science had once claimed to be 鈥渘atural鈥�. Race came to be recognised as a social construct 鈥� an aspect of social choices rather than a reflection of biological differences between racial groups.
The constructionist thesis gained popularity after the second world war and encouraged advances in civil and human rights for racial minorities. And with the Human Genome Project finding in 2000 that all humans are more than 99 per cent alike, many thought genomics would put the final nail in the race coffin.
But a funny thing happened on the way to the funeral. Shortly after the HGP鈥檚 finding, several research projects began focusing on mapping this less than 1 per cent of human genetic variation onto social categories of race.
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This small variation reflects millions of SNPs (single nucleotide polymorphisms), some of which may loosely correlate with geography. Yet the resilience of linking such differences and disparities to biological mechanisms is striking, since most analysis of the data cautions otherwise.
Some uses of new technologies also reflect this renewed effort. Though they explicitly reject the scientific racism of the past, race is given genetic significance in an effort to resolve health disparities, provide a richer sense of ancestry, and aid law enforcement.
Take the drug Bidil, the first drug in the US to be marketed, and approved by regulators, for a specific racial group: blacks suffering from heart failure, a group thought to be disproportionately affected by the condition. This allowed its supporters to make claims about the regulatory, legal and economic relevance of race and genetics, reinvigorating the idea that biological mechanisms are primarily responsible for racial disparities in health.
Indeed, the chair of the committee that recommended Bidil鈥檚 approval noted that his group took self-identified race in the drug鈥檚 clinical trial 鈥渁s a surrogate for genomic-based medicine鈥�.
Bidil is a key example of how, as in past eras, the presumption that race reflects inherent differences can shape the very differences researchers seek. First, Bidil was not designed as a race-specific drug. Rather, its makers found a race-specific effect after it failed to win approval as a non-race-specific drug. Moreover, the clinical trial mounted to demonstrate that Bidil was race-specific only included individuals who self-identified as black, so the results of this trial tell us nothing about whether it works better in one group than another.
Lastly, no genetic data was submitted to the regulators to support the idea that Bidil鈥檚 purportedly unique benefit for blacks stemmed from some type of genetic tailoring. The notion that race can be used as a surrogate for genomics is far from evidence-based medicine.
Similar problems plague genetic tests for ancestry. While many companies make big claims, the techniques used are limited. Mitochondrial DNA and Y-chromosome tests can identify to a high degree of certainty whether two individuals are related; they are less useful when used to tell consumers their relationship to various populations, because the tests examine less than 1 per cent of anyone鈥檚 DNA.
It is important to emphasise that there are no genetic variations exclusive to any racial group. Some are more common in certain populations, but their distribution does not align with social categories of race.
鈥淭he distribution of genetic variations between populations does not align with categories of race鈥�
Moreover, the genetic databases held by companies that attempt to connect customers to specific populations contain such small samples that what initially looks like a unique marker for a group may, after broader sampling, turn out not to be. This partially explains why individuals taking multiple tests often receive conflicting results.
In criminal investigations, DNA evidence has helped exonerate thousands falsely accused. Yet there remain troubling questions for racial minorities whose disproportionate contact with the police means they are more likely to find their DNA on police databases. In the US, for example, blacks make up about 40 per cent of the federal offender database while constituting only about 12 per cent of the population. Policies such as including people merely arrested for certain felonies will only exacerbate this.
Other applications, such as molecular photofitting, where scientists attempt to create a physical profile of a suspect by examining biological materials at a crime scene, also fuel the idea that racial difference presents itself discretely at the molecular level.
The presumed infallibility of DNA technologies can lead prosecutors, judges and juries to not fully appreciate these technologies鈥� potential for injustice, which bodes poorly for racial minorities.
Without due care, some uses of commercial and forensic biotechnology may revive the myth that social categories of race reflect genetic boundaries of human difference, and that the social and health outcomes of groups are determined by genetic predispositions rather than social forces and institutional practices.
Given our unfortunate history of linking biological understandings of race to racial hierarchy, we cannot afford to ignore how new technologies may revive old theories of race. The future of our concepts of race and equality may be at stake.