The school year at the University of California, Berkeley, began with a swab. In a program called Bring Your Genes to Cal, 5,500 incoming freshmen were asked to provide samples of their saliva in an experiment designed to bring the student body together in the same manner that reading To Kill a Mockingbird might have in the past. The more than 700 students who responded had their DNA analyzed in Berkeley’s (uncertified) labs, assessed for susceptibility to alcoholism, lactose intolerance and relative metabolism of folic acid. The exercise provoked an international debate about the ethics of the assignment. Ultimately, the California Department of Public Health barred the university from dispensing individual profiles on the grounds that genetic analysis is correlative only and is neither necessarily predictive nor diagnostic at this point. A collective comparison of the class’s genetic data was permitted, however, and circulated in "anonymized" form at orientation.

There are several reasons that Berkeley’s undertaking should give us pause. The first and most obvious is that of privacy: this information reveals more than we can yet interpret at the singular, embodied level of human identity. DNA decoding will become infinitely more precise in the near future, and with that growing precision in familial tracking and biological identification, "anonymizing" results by removing names and Social Security numbers will mean less and less.

Second, Who owns, or ought to own, these data? Although the Berkeley experiment is framed as an exploration of a vast genetic commons, this information is the subject of intense commercial speculation. And the degree to which specific gene sequences may be patented is quite contested in the law. Should you, as the biological vessel of a particularly exploitable bit of genetic material, receive any remuneration? Are your genes to be valued, in purely pecuniary terms, as akin to a deposit of oil beneath your land? Once genes are patented, can rival researchers be barred from working on the same material?

Another problem with Berkeley’s DNA swabbing is that it perpetuates the assumption that DNA analysis is as good as or the same as personalized medicine. Despite large gaps in understanding and the astonishing absence of standards, the results of genetic research are often held as being far more definitive than yet shown. The mere phrase "genetic correlation" is heard as a 100 percent infallible guarantee of whatever follows. This assumption is often implicit in the advertising of some direct-to-consumer companies like Navigenics and 23andMe. Indeed, both companies were hired to analyze the results of a medical school class’s "spit party" at Stanford University recently.

On July 22, however, the Government Accountability Office issued a report that advised consumers of the scientific uncertainty of individual results, in which assessments of risk varied widely from company to company. The GAO also found "10 egregious examples of deceptive marketing, including claims made by four companies that a consumer’s DNA could be used to create a personalized supplement to cure diseases. Two of these companies further stated that their supplements could ‘repair damaged DNA’ or cure disease, even though experts confirmed there is no scientific basis for such claims…. Two other companies asserted that they could predict in which sports children would excel based on DNA analysis, claims that an expert characterized as ‘complete garbage.’ Further, two companies told GAO’s fictitious consumer that she could secretly test her fiance’s DNA to ‘surprise’ him with test results—though this practice is restricted in 33 states. Perhaps most disturbing, one company told a donor that an above average risk prediction for breast cancer meant she was ‘in the high risk of pretty much getting’ the disease, a statement that experts found to be ‘horrifying’ because it implies the test is diagnostic."

This is not to say that genetic testing shows nothing at all, but the results inform only at the aggregate level or as a set of probabilities. This explicitly aggregate data collection has been the subject of yet another controversial program, called Gopher Kids, conducted by the University of Minnesota at the annual state fair. At a booth adorned with balloons and a cute animal mascot, researchers offered free T-shirts and amusement park rides to parents and children willing to submit saliva swabs and answer a lengthy questionnaire about lifestyle. The university advertises participation as altruistic, a contribution to public health and human knowledge. The problem with this is that, again, the law is not settled about whether our genetic makeup is more the property of the excavating mind of the scientist or the individual property of a particular identified body.

Finally, there is the question of motive. Spit parties are boosted as ways to get to know one another in the social realm—as though it were a collective séance or a big, slimy Ouija board. But the real reasons that so many companies market swabbing kits is not entirely altruistic: there is huge money to be made in expanding the data sets as broadly as possible. The predictive probabilities involved in reading genes for disease or physique or ancestry can become more precise only by sifting through data of whole populations and then correlating frequencies of particular conditions with particular genetic clusterings. This, it is thought, will be very valuable in devising and marketing pharmaceuticals, as well as in forensic identification technologies.

As we enter the genomic era, we should be more thoughtful about the ends for which our bodies are being mined. The redemptive thrill of being co-creators of some medical miracle must be measured against the possibility that we are rendering fungible that which most profoundly distinguishes us and, in the name of a gift, enabling a commodity exchange in which important aspects of our identities will be sold to the highest bidder.