Wednesday, October 27, 2010

A teachable moment

There are two things I want to discuss in this post. Though at first glance seemingly unrelated, they will fit together in the end.

As I already mentioned here, I utterly delighted in Dan Ariely's erudite account of our predictable irrationality. In this book, he reminded me of a thought experiment initially conceived by the recently deceased philosopher Philippa Foot. The problem is usually referred to as "the trolley problem", and can be presented in several ways. Here is how Joshua Greene at Harvard formulates it:

   First, we have the switch dilemma:  A runaway trolley is hurtling down the tracks toward five people who will be killed if it proceeds on its present course. You can save these five people by diverting the trolley onto a different set of tracks, one that has only one person on it, but if you do this that person will be killed. Is it morally permissible to turn the trolley and thus prevent five deaths at the cost of one?   Most people say "Yes."

   Then we have the footbirdge dilemma:  Once again, the trolley is headed for five people. You are standing next to a large man on a footbridge spanning the tracks. The only way to save the five people is to push this man off the footbridge and into the path of the trolley.  Is that morally permissible?  Most people say "No."

    These two cases create a puzzle for moral philosophers:  What makes it okay to sacrifice one person to save five others in the switchcase but not in the footbridge case?  There is also a psychological puzzle here:  How does everyone know (or "know") that it's okay to turn the trolley but not okay to push the man off the footbridge?
Indeed, if the sum total of deaths is the same, how is it that one seems OK, while the other does not? Is this just a bunch of irrational emotional baloney, or is there science that can shed some light on it? Well, as it turns out, Greene has postulated the "dual process theory" of moral judgment. He has performed brain imaging to understand better what is happening physiologically, and here is what he is finding:
   According to my dual-process theory of moral judgment, our differing responses to these two dilemmas reflect the operations of at least two distinct psychological/neural systems.  On the one hand, there is a system that tends to think about both of these problems in utilitarian terms:  Better to save as many lives as possible.  The operations of this system are more controlled, perhaps more reasoned, and tend to be relatively unemotional.  This system appears to depend on the dorsolateral prefrontal cortex, a part of the brain associated with "cognitive control" and reasoning.

  On the other hand, there is a different neural system that responds very differently to these two dilemmas.  This system typically responds with a relatively strong, negative emotional response to the action in the footbridge dilemma, but not to the action in the switch dilemma.  
When this more emotional system is engaged, its responses tend to dominate people's judgments, explaining why people tend to make utilitarian judgments in response to the switch dilemma, but not in response to the footbridge dilemma.
So, here is the science to explain what we already know intuitively. It underscores just how difficult risk-benefit decisions are, and that if we only take into account our rational selves, we will always walk away puzzled as to why it is that there is controversy about stuff, such as, say, interventions in healthcare.

So, this is point one. Point two illustrates how counterproductive acrimony can be in trying to achieve some common ground. There is a response from Orac on Dr. Novella's site here, which calls me on the use of the adjective "rabid" to describe vaccination "defenders". Without explicitly stating it, he also continues to equate me with "anti-vaxers". But also does something else: he provides a link to a previous post that I did in the middle of the H1N1 pandemic. Please, indulge me for a moment while I quote myself:
The H1N1 pandemic is bringing into focus not only the world's vulnerabilities vis a vis the spread of an infectious disease, but also our complete lack of a framework in which to make rational choices about prevention. The cornerstone of preventive efforts for any significant infectious disease is vaccination of a large swath of the population. The rapid development and approval of the H1N1 vaccines is both a blessing and a curse, given the sophomoric level of discussion about its risks and benefits.
Does this look like I am anti-vaccination? Indeed, it looks to me, and this reflects my intellectual stand, that I am in fact advocating for vaccination, as well as for bringing our vaccine discussion to a more scientifically literate level. Feel free to read the entire post, if you do not believe me. But what is obvious is that my name-calling resulted in people, who consider themselves otherwise rational, paying attention only to the insult. Thus, I negated the substance of my post just with one poorly chosen word. Is this a rational reaction to what is otherwise a perfectly pro-vaccination stand? I do not think so, but what it is is a human reaction, and in that it is perfectly understandable and, dare I say it, predictable.

In fact, the post in question ties the two seemingly unrelated ideas, as promised at the beginning.  Although admittedly not very skillfully, in my vaccination post I illustrated the trolley problem, where the accounting of the balance of risk-benefit is not at all straight-forward. I will probably address it more extensively in a future blog post. On the other hand, I also showed how one single insult in a 500-word essay can become the only take-away, thus detracting from the overall message. This is exactly the reason for us to stop the name-calling by both sides, and engage in a discussion to arrive at some mutual understanding of what is really a worthwhile exchange of ideas.  


  1. "Without explicitly stating it, he also continues to equate me with 'anti-vaxers'."

    Spare me.

    I've said multiple times that I don't think you're antivax. However, you do use language very similar to that of antivaxers. The reason, as I have said, is almost certainly ignorance. You clearly aren't familiar with the fallacious arguments and abuses of science by antivaxers; so you unwittingly start sounding like one. Let's clarify from my most recent post (

    "Let me also say that I believe her [Dr. Zilberberg] when she says she is not anti-vaccine. Even so, she carelessly throws around rhetoric that, whether she realizes it or not, echoes a lot of anti-vaccine rhetoric. (And who is more of an expert on anti-vaccine rhetoric than I? Not many.) As Steve so aptly put it, what she's doing is akin to someone expressing skepticism towards some aspect of evolution and thereby appearing to support creationism because she doesn't know the ways creationists distort and abuse science in the name of attacking evolution. She does the same thing here with vaccines. For example, elsewhere on her blog, as I mentioned before, Dr. Zilberberg referred to "rabid defenders of vaccines," while complaining about the lack of philosophical exemption laws in most states. Let's put it this way. If you don't want to be perceived as an anti-vaxer, don't refer to defenders of vaccines as "rabid" and don't start referring to the possibility of vaccine interactions in a way that is reminiscent of the arguments that anti-vaccine advocates make. I realize that Dr. Zilberberg's mistake is probably due to ignorance of the corrosiveness of the anti-vaccine movement, the depths of pseudoscience to which it regularly descends, and a lack of familiarity with their fallacious arguments, but hopefully this exchange will serve to educate her to be more careful in the future."

    Apparently I hope in vain.

  2. Dear Orac,

    Thanks for your comment. To me the issues are quite complicated. I understand your fatigue with what you call "rhetoric", but the whole point is to see the nuances and not to discard people based on a partial disagreement. Equating this debate to the creationism vs. evolution is not productive. There will always be wingnuts on both sides, but would you not instead of neatly filing arguments, prefer to be in a real conversation that eventually may lead to a better understanding?

    You and Dr. Novella are correct, by the way, I have nothing but knowledge to gain through these discussions. And if you think that I enjoy being called ignorant, you are mistaken. But I am more interested in getting to an enriching conversation than in throwing around expletives. You both clearly have a lot to say on the issues, and would it not be nice to have the other side of the argument focus on what you are saying rather than on personal attacks? Is it not self-evident that we need to elevate the discussion to its proper scientific level? And educate the lay public about the components of these decisions? That is what I ma advocating.

    I see what polarizing politic and news are ding to our country. We have the opportunity to challenge the fallacy that everything is so black and white that those who disagree with us are idiots. Yes, some are, but most, I bet are not, and like the voters in this election, are turned off by the pitch and rhetoric. So, I invite you to a quiet and intelligent discussion about the issues that we are both knowledgeable and passionate about.

  3. Dr Z,
    Thanks for the footbridge and switch dilemmas. I'm enjoying the discussions and perspectives of all involved. The intensity of many comments and the assumptions behind the intensity intrigues me. The rhythm of the process is of interest to me also. I admire your regrouping comments that reunite the potential for learning.
    I'm pleased by the scientific part of the debate and reminded of the process used by renowned local inventors, Orville and Wilbur Wright. Their father, Bishop Wright would stop them in the midst of intense debate about a variety of subjects and make them switch sides. They continued to use this process as they worked their way through their many inventions, including the wind tunnel, the airport, the flight school, the airplane and others.

  4. Dear Dr S, thanks for your comment and the anecdote. It is indeed a valuable exercise to put oneself in the other's shoes.

  5. I think that Orac is a master of using logic and rhetoric for skewering the flies of "alternative medicine" while ignoring the rampaging elephants of "scientific medicine." My criteria is the number of people injured and the amount of economic resources wasted.

    He has considerable intelligence but appears to me as so focused on defending medicine against the perceived "wackos" that he tends to ignore the weaknesses and dangers of the far more influential forms of medicine. This is a shame as we would all benefit greatly from a re-focusing of his talents.

  6. Duncan, thanks for your comment. I have been thinking about this very issue, and am grateful for your lucid characterization of the problem.