Genetic Future

Razib has crunched the numbers from the General Social Survey (a massive longitudinal study of societal trends) to explore the variables associated with response to this question:

Some people say that genetic testing may cause trouble. Others think it
is a wonderful medical advance. Based on what you know, do you think
genetic testing will do more harm than good or more good than harm?
[my emphasis]

The major finding: by far the strongest correlation is with attitude towards the Bible (those who regard it as the Word of God are more skeptical of testing), with position on the political spectrum taking second place (with conservatives being more skeptical than liberals or moderates). That’s not a shock, but I am surprised by how weak the correlation is between response and both socioeconomic status and education level – in both cases there’s a trend towards more positive responses at the higher end of the spectrum, but it’s either marginal or not statistically significant.

The reason I’m surprised is that I would expect attitudes towards testing to be influenced considerably by levels of knowledge about genetics (with more informed people, in general, being more favourable towards testing; this has certainly been the trend in previous surveys I’ve seen).

While the trends certainly point in that direction both educational level and SES are only weak proxies for genetic knowledge – and fortunately the GSS also included a question (GENETST1) that provides a more direct estimate of genetic literacy:

1564b. How much would you say you have heard or read about genetic testing?

Responses could be “A great deal”, “Not very much”, or “Nothing at all”.

I used the SDA interface to look at the relationship between the response to this question and the “good vs harm” question above. Here’s the graph:

i-df7fa3e166033c7f09f0afdc9ef4c0ba-gss_genegoo2-vs-genetst1.jpg

For each bar, the area in red indicates those who were favourably inclined towards genetic testing (i.e. believed that testing will do more good than harm), while the blue area indicates those who were skeptical about the benefits of testing. In total 2,460 people answered both questions.

The result is a visually obvious and highly statistically significant trend (P < 10-9, Chi-squared test): the less familiar you are with genetic testing, the more likely you are to see it as harmful overall. Among the 483 individuals who rated themselves as knowing “a great deal” about genetic testing 80% had favourable views; among those who said they knew “nothing at all” that figure dropped down to 57%.

In other words, fear of genetic testing is strongly correlated with self-reported ignorance.

Of course, there are some caveats: firstly, self-rated familiarity is not necessarily a good indicator of actual knowledge level (although it seems likely that it will be a reasonable proxy); and more importantly, correlation doesn’t tell us about the direction of causation. Seems like there are some more variables in the GSS data that might help unravel this issue a little more cleanly, so I might have more to say about this once I’ve run a few more analyses.

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Comments

  1. #1 Steven Murphy MD
    April 12, 2009

    I am surprised they found so many people who are very familiar with genetic testing….I am highly skeptical of just how familiar they really are…

    I.e. Oprah familiar or college educated familiar…

  2. #2 Reed
    April 12, 2009

    In other words, familiarity with a subject lessens one’s fear of it. The problem is that familiarity is not the same as being able to objectively evaluate the harm or lack of harm of a particular activity. For instance, I imagine that those who are accustomed to female circumcision find it less fearful than those who aren’t accustomed.

  3. #3 Daniel MacArthur
    April 12, 2009

    Hi Steve,

    Well, the question only asks how much they have “heard or read” about genetic testing – so “A great deal” doesn’t mean they think they’re experts on the subject, just that they’ve come across the topic many times (e.g. on the news). So this is more a measure of familiarity with a topic rather than deep understanding – as you say, more Oprah than college degree-level familiarity.

    Obviously the categories are somewhat arbitrarily placed on a sliding scale. Perhaps the best way to think of it is just to regard the first and last categories as representing the top 20% and bottom 11%, respectively, of self-reported familiarity with genetic testing.

  4. #4 Mr. Gunn
    April 12, 2009

    Perhaps the reason Razib didn’t find the association is because of the independent correlation between level of religiousity and education?

    Nonetheless, very interesting and not at all surprising.

  5. #5 Mary
    April 12, 2009

    Well, I’m not sure I would answer the way you would expect based on my knowledge of the field. For Americans not all the issues are on science. GINA still isn’t even in effect, and I don’t think I am comfortable with most testing at this point. Our health insurance status is too precarious, and only worse now in times of economic uncertainty.

    I think there is potential for advance. There’s also potential for misuse by quacks that is becoming more and more apparent to me as I’ve been tracking some genetics issues in public debate (autism, GMOs).

    And what we can know vs. what is worth knowing is still very different.

  6. #6 Daniel MacArthur
    April 12, 2009

    Hi Mary,

    Sure, there are many ways that genetic testing could do harm – but do you genuinely believe that, overall, genetic testing will do more harm than good? In other words, that health insurance problems and quacks will outdo all of the potential good resulting from genetic health predictions?

    It’s not a leading question – you’re someone who unambiguously has a solid knowledge of genetics, so if you do have this opinion I’d be intrigued to hear it.

  7. #7 Mary
    April 12, 2009

    If I was able to break the question in to categories: can testing do harm/good for medical aspects, I would say of course. Eventually. But even that I would qualify with the fact that we don’t have enough preventative interventions for most of the things we need yet. And still, even with GINA, I don’t think we are safe from our health care system at this time. GINAs scope is not really completely comforting to me.

    Can testing do harm/good for society, I would have to say possibly. A member of my family recently changed her diet based on the “Blood type diet” or some quackness like that. I know people will spend serious money and time trying to fix or cure things that will be of no value, and make them crazy. I’m regularly doing battle on vaccine fallacies based on bad science–even among people who should know better–and it’s clear that infectious disease control was a huge winner.

    People aren’t able to evaluate things critically enough at this point. They are going to get taken by charlatans and waste way too much brainpower on genetic ghosts.

    The question itself does not specify medical vs societal, and it doesn’t specify the time frame. So my answer would be to average those mentally and I’d probably have to answer in the middle.

  8. #8 Daniel MacArthur
    April 13, 2009

    Hi Mary,

    Thanks for expanding on your argument.

    The health insurance issue has always seemed quite alien to me, given that both my native country (Australia) and my current home (UK) have quite socialised health systems and a political climate that would make it near-impossible for serious genetic discrimination to persist – but I am beginning to understand the serious concerns from a US perspective. Hopefully the approaching legislative changes will help to reduce some of these fears.

    On the quack front I am less convinced. I have little doubt that we’ll see a major crackdown on DTC genetic testing (both in Europe and the US) within the next year or two that will help to weed out the more egregious examples. After that, quacks will of course persist in some form – but I’m skeptical that their effects will be anywhere close to sufficient to counteract the health benefits of predictive testing.

    Anyway, I guess we’ll know one way or another within the next few years!

  9. #9 Mary
    April 13, 2009

    Hi Daniel–

    I guess I’m not worried about the specific _testers_ so much. Although I was assured on a blog that one guy wanted to do BRCA1 testing in his basement as DIY biology because he hated that someone had that patented. He wanted to offer back-alley testing to his family and neighbors. But that’s small scale.

    But I’m worried about the quack interpretations. Say you get tested by one of the approved/accredited providers. Then you have a list of variations. There are going to be people who create “treatments” and “diets” and other sorts of woo around that outcome. Not the specific testing itself.

    I guess I’m particularly sensitive to this right now because I’m watching some anti-science activists trying to actively disrupt legislation here on a different genetics topic (GMOs). There are zombie internet myths around that topic that are actually driving activism. It’s created a quasi-religious belief system that I think is creating a new class of eating disorders (Orthorexia nervosa, which I realize is not an official diagnosis at this time–but I have actually seen people going this way more and more.) They are driving themselves nuts trying to control things that go into their bodies. I think having certain alleles will push more of them over the edge on this type of behavior.

    Maybe it isn’t a legitimate parallel. But I could envision it going that exact same way.

  10. #10 Daniel MacArthur
    April 13, 2009

    Hi Mary,

    OK, I completely agree that genetic testing will serve as a trigger for all kinds of woo. On the other hand, if the alties weren’t circling around genetics they’d just be imbibing nonsense about some other facet of science, probably something with the word “quantum” in it.

    In other words, I’m unconvinced that increased genetic testing will increase the total amount of woo in the world; it will just give the same old set of crazies a different field to play in.

  11. #11 Daniel MacArthur
    April 13, 2009

    (By the way – to readers who (like me) had never heard of “orthorexia nervosa”, here’s the Wikipedia entry. Interesting stuff.)