I submitted a DNA sample to 23andMe, and now they send me periodic updates on what they’ve figured out lately from my genes. For instance, they’ve informed me about traits I might have.
This is strange. I know what I take away from it, but I wonder what the general populations learns from this kind of list. Here are the two important messages I learn from this kind of revelation:
- Notice all the “likely”s and “less likely”s? That will never change, because if there’s one thing we can be confident of, it’s that every trait is the product of multiple genes interacting in complex ways. It says I’m not likely to have a cleft chin, but I know for a fact that under my beard there is a cleft chin, and that I’ve passed that on to my children and inherited it from my father. It doesn’t mean 23andMe did something wrong, it means that they’re missing information about all the factors that contribute to chin shape, and are estimating from knowledge of a few genes. They’re drawing on correlations in the large database that they have, but can’t infer mechanisms or the full range of interactions that occur during jaw development.
What’s really depressing, though, is how trivial all these traits are. Does anyone really care that I’m less likely to get dandruff? Wouldn’t I get better information about that by checking my shoulders than by analyzing my DNA? Part of the reason for the triviality is that they also have a “health report” that they charge extra for which summarizes more substantial predilections, which I haven’t paid for. It would have exactly the same kind of probabilistic statements. It might, for instance, say I’m genetically predisposed to heart disease, but I could probably guess that from the fact that my father died young of heart disease, and would be better off going to my doctor to have my cholesterol and blood pressure checked (as I do regularly, and no worries — I’m in good shape for a man of my age).
So what I take away from this is a lesson in uncertainty and doubt; is that the information they’re trying to share with the general public? Because that’s not what I get from their “traits tutorial”, which starts off “Our Traits Reports are a fun way to explore how your DNA makes you unique.” Where’s the fun? Where’s the uniqueness? Am I special in my resistance to bunions, or am I supposed to be entertained with the news that I probably have blue or green eyes? (Not blue, by the way, more green, kind of hazel; I usually say they’re the color of rich algal swamp mud).
My general impression is that this is “fun” in the way taking Myers-Briggs tests and horoscope readings are fun; it’s mostly bogus, phrased in a way to seem positive, and we can poke through them for affirmations of stuff we were pretty sure of, already.
I signed up mainly for the ancestry component, but even there, it’s vague.
My god, I’m a white guy! Who’d have guessed?
Meanwhile, this is just nonsense.
Yes, I’m a member of haplogroups that include European royalty, which is true of almost all the white people from Northern Europe. You might as well announce that I have pale skin, just like the kings and queens of old Europe! Whoop-te-doo! I am fun and unique.
I am not opposed to the idea of 23andMe, and think they’ve gathered a lot of potentially useful information. I just feel that the way its presented to the public is biased to reinforce false ideas of genetic determinism to induce people to participate, and that worries me.