Nightline gets caught in genetic testing trap
ABCNews Nightline last night became the latest news organization to get tripped up by the genetic testing industry. It's an irresistable story: Should I or shouldn't I find out what my genes say about my genetic destiny?
Alas, in 2008, it's the wrong story to be telling about genes. The premise of the question is false. With very rare exceptions, genes simply don't work that way. Genes are not, as we were all taught, self-contained packets of information dictating a specific blueprint design for each individual. Rather, they interact with each of our unique environments from the moment of conception to the moment we die. That's why genetic tests won't be able to tell us if are going to get a disease; all they can tell us (again, with some rare exceptions) is whether or not, statistically, we are slightly more or slightly less likely to get a disease than the average person.
So last night Martin Bashir found out that he has an increased risk of Type II Diabetes -- 19% rather than the average of 11.2%. He also has an increased chance of becoming obese.
But when you think about it, that percentage doesn't really apply to him as an individual -- it's only a population average. It's not any different from measuring the height of 100,000 people and then telling each one of them whether they are more or less likely *than average* to become a pro basketball player. There are so many other influential factors at play in any individual life, the "disposition" means almost nothing. It's useful to statisticians, useless to individuals.
I don't want this to be one of those bash-the-press blogs, because absolutely any good journalist would be expected to miss this story. That's because most of the scientists themselves have done such a poor job of correcting the extraordinary misperceptions about genetics. We're fighting an entire century of misleading metaphors about genes.
And I should point out that, toward the end of the Nightline piece, they did get the real point. After leading us in one direction for quite a long time, they closed with a quote that challenged the premise of the piece itself.
Hank Greely, a Stanford law professor, said it beautifully: "We both fear and love the idea that somehow our genomes are us, that everything about us is defined by this long sequence of as CS GS and TS. You know, it's just not true. For most of us, the events that have happened during our lifetimes our parents' efforts for us, the friends' we've made, the jobs we've had, the good and bad luck we've had that's more important in who we are than what genes we're born with. And that's really important to remember."
"Genes are, except for a very few unfortunate people, not destiny, they're influences, they're not destiny," he said, "and if we think too heavily that they are destiny, we are going to mess ourselves up."
