One of the ways genetic science has captured the public’s attention is in the way it allows us to believe that understanding one’s DNA leads to understanding deeper truths about people. The fully mapped and sequenced human genome has been called the book of life, since it contains all the genetic information necessary to construct human beings. But does genetic information tell us all we need to know about a person? Hardly. If we really want to know a person—their character, hopes, ideas, beliefs, sense of humour—genetic science can only get us so far. DNA is not destiny. And while we’re at it, maybe we should also dispense with public opinion surveys, focus groups, standardized tests, voting records, and bar code results from grocery purchases. Instead, why don’t we simply have a look at the books stacked on their bedside nightstand.
The thinking goes like this—whereas opinion polls and other strategies for eliciting attitudes have statistical validity, they can never authentically capture more nuanced ideas about why people think the way they do and what matters to them. Books, especially books you choose to read, ought to reflect more of who you are. And the books on your bedroom nightstand may say the most. At this moment I have eight: a new historical account of the Medical Committee for Human Rights written by John Ditmer; Matt Ridley’s The Rational Optimist; a compendium of Stephen Jay Gould’s essays by Steven Rose; Greg Mortensen’s second book, Stones for Schools; a couple of Clive Cussler novels; a scuba diving guide from the “Dummies” series; and a book about losing belly fat (which actually seems to be working). There is no formal order to the pile: the books are partially stacked, partially piled. Nor are they in any rational order, except perhaps that the most recently read is on top and the widest one (Rose’s compendium of Gould) is good for holding my reading glasses.
Of course, many people have books piled on nightstands, likely organized (or not) in different ways. Aesthetics aside, books on nightstands reflect their owner. In my case you would correctly gather that I have an interest in evolutionary biology, human rights, personal health and scuba diving. But how much can we generalize from this? For example, looking at my nightstand today would give you a current snapshot but not a full picture. Two months ago Ridley and Rose hadn’t been purchased; instead you would’ve found a Lonely Planet Guide to Perth and Western Australia and Jack Weatherford’s Ghengis Khan and the Making of the Modern World (to read along with my daughter reading it for a high school summer assignment). Who knows what the pile will be in two months, let alone two years?
So it is with DNA. In some cases you can learn that a tiny misspelling in a person’s genetic alphabet greatly increases their chance of developing a disease or responding to a drug. This is good and useful. But genetic information will not reveal all. Moreover, we are now learning that small changes in the environment may actually trigger differences in how genes work.
Perhaps I have just proved the negative: using the content of one’s nightstand as a method for more deeply understanding an individual has some merit, but it has to have inherent limitations. Again, it’s the same with DNA. But it seems the public has a different take on this, which is problematic. You can hardly read a major daily newspaper (or its online equivalent) and not find survey results of public attitudes on stem cell research, organ transplantation, health reform, or genetic testing. And the snapshot approach—telephone, mail or online surveys—is often what’s used to capture public opinion. These snapshots are limited by the questions asked, how they were framed, and what the respondent was thinking at the time, as is the case with any opinion survey. One could also take the long view—by examining, for example, all the books I’ve piled on my nightstand over the years (and the thousands of books on hundreds of nightstands over many years). Like many, it would be a pretty long list—rivers of reading material have come into my life, eddied for a time (some longer than others since I am always reading more than one book) and then moved on with the current, taking completed (or unfinished) books to the second-hand book exchange my wife uses or to friends and colleagues. The river-of-books-over-time approach is analogous to large longitudinal cohort studies in which scientists track a population over many years. The Framingham Heart Study in Massachusetts has been ongoing for more than sixty years; researchers have been following the residents of this small town over their lifetime to see how they lived and died, how many got sick and of what, and at what age people had heart attacks or strokes. They occasionally interview them, ask them to complete surveys, and take small blood samples for genetic analysis. If only there was a way to do this with the books on our bedside tables.
Taking the long view gives a much better picture of populations at a depth that no poll can ever touch. Similar efforts are underway with large biobanks—repositories of DNA, blood and other biological materials often linked to health records that are being developed around the world. Like the Framingham study, these biobanks are now being mined for genetic data, which researchers hope one day to turn into health information that can aid in preventing and treating disease. They are valuable tools to learn about what makes people healthy or sick, at high or low risk. But of course they can’t tell you anything approaching a person’s life goals or plans. Genetic analysis isn’t any different; it can’t tell you who people are or what is important to them.
So how, then, ought we try to understand the connections between genetic data about a person, and the person herself? How do we make sense of a survey outcome about someone’s beliefs about genetics, and the profound complexity that make up the beliefs themselves? And how do we translate genetic knowledge obtained from a tiny piece of DNA extracted from a blood sample into an eventual treatment plan for people with a common disease? It’s not so much that genetic science is flawed; it’s that it’s incomplete. Maybe the public needs to learn more about science, a lot of which they’ll find in books. And of course it’s not that books are unable to provide some information about what people are like, it’s just that it’s more important to hear what people say about the books they’ve read. DNA may be called the book of life, but it’s never going to be a replacement for the books in my life.