By Samuel W. Anderson

If you are even an occasional GeneWatch reader, you are probably somewhat familiar with the format we've used for most GeneWatch issues over the past several years: Pick a topic worthy of discussion and assemble articles from intelligent people who have intelligent things to say about that topic. You're probably also accustomed to many of those articles taking a critical tack, and sometimes getting into a rather heated discussion of a contentious topic.

And having read the cover of this issue, and perhaps the articles listed at the bottom, you may be thinking something like: "OK, I can see how 'Ancestry and DNA' would be a contentious topic when it comes to something like definitions of 'race.' But DNA ancestry testing? This is the thing my great aunt was showing everyone last Thanksgiving as proof that we might have a Seminole ancestor just like she always said? Is that really such a contentious topic?"

Firstly: Yes, this is the thing your great aunt brought to Thanksgiving. And secondly ... well, you're right, it doesn't sound like a particularly controversial topic. And in some ways, it really isn't. This may be a very American perspective, but it seems to me very natural to be curious about one's family history, and I'd argue that any sort of curiosity is, broadly speaking, a good and healthy thing. It's also fun to imagine discovering a surprise in your family history - and, if you find one, to imagine how it came about - and I'd argue that imagination is, broadly speaking, a good and healthy thing. So really, as a source of entertainment, genetic ancestry tests seem quite benign.

But beyond their entertainment value, these tests are not always so innocuous, starting with the very business model of most DNA testing companies. Since few people will buy an ancestry test more than once, what will these companies do when they inevitably start to run out of customers? Actually, they'll just be getting started. As Patricia Williams and Robert Pollack explain:

In effect, there's a kind of bait and switch going on. The real asset of these enterprises is the collective data siphoned from individual consumers. The wealth that will be the return on corporate investment is premised on building large enough data sets - from millions of individuals ideally - to extract much more accurate associations, trends, patterns. The goal is to be able to sell insights about large-scale population genetics. Unfortunately, this much has little to do with what purchasers of the kits think they are getting. In the meantime, companies seem happy to have gotten consumers to actually pay them by handing over the gold of their DNA in exchange for often largely unsubstantiated surmise about relation to ancient princesses or the consistency of one's earwax.

The companies that are doing well in this regard aren't necessarily hiding the fact that they are in possession of so many individuals' genetic information, but they frame it as a benefit to the customer.'s DNA testing branch, ancestryDNA, boasts "A massive DNA collection" as one of its selling points: "We've assembled one of the most comprehensive DNA datasets from around the world to compare to your DNA signature and help determine your ethnicity." National Geographic's Genographic Project leads off its own pitch to consumers similarly: "Join the more than half a million people who have already taken part ..." (To their credit, the Genographic Project openly acknowledges that the main reason the project exists is to use the DNA collected for research - in fact, this is also presented as a selling point, a sort of approximation for donating one's body to science.)

There are also some fundamental issues with the way these tests are marketed, especially when that marketing influences the way customers read their results. One of the overarching themes is the conflation of DNA and self-identity, the idea that the results of an ancestry test will help you to better understand yourself. Take this customer testimonial from the ancestryDNA website:

"I am so happy to have taken the DNA test as it solidified my findings and gave us the TRUE ancestry of my family!"

Just to clarify, I didn't add the capitalization for emphasis - that's the quote, verbatim. Across the various ancestry testing sites' sales pitches, customer conversations in message boards, and even in some of the more prominent media coverage of DNA ancestry testing, some variation of this notion is repeated: "Now that I have these results, I know who I really am."

Anytime you hear that sort of fatalism, you have to raise an eyebrow. As Williams and Pollack point out, despite how often we're led to believe that our DNA is our destiny, our environment molds us in equally fundamental ways. The past decade's discoveries in epigenetics have shown us that environmental factors can even alter our genetic code itself.

This science is a big part of what makes such genetic determinism so unsettling, but it can be trickier to translate molecular biology into answers to big questions about self-identity. DNA ancestry testing can definitely raise that sort of question. If you find a surprising result, should you think differently of yourself? If a DNA test reveals 5% South Asian ancestry you never knew about, does it change who you are?

In this case, our understanding of the interactions between genotype and phenotype translates easily enough: When it comes to shaping who we are - the content of our character, certainly, but even to a large extent our physical attributes - we owe much, much more to our friends, coworkers, and neighbors than to the one sixty-fourth of our DNA contributed by a great-great-great-great grandparent, no matter how exotic their origins. And nothing you learn from an ancestry test comes close to the influence wielded by the most important shaper of your physical, mental, and emotional self: You. 

Samuel Anderson is Editor of GeneWatch

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