A mother was describing to me how her child had been vomiting over the last few days. ‘And I know just before he’s going to be sick,’ she told me, ‘because the sides of his nose turn yellow.’ She looked at me significantly, as if she was assuming that the yellow nose sign would mean something to me as a doctor and lead me to the exact diagnosis.
Patients’ narratives are full of these kinds of descriptions. Mostly doctors do not even hear them – quite literally. If you watch videos of your own consultations, you find that there are details in every history, mostly about yellow noses and the like, of which you have no recollection. Because they do not fit the medical view of the world, doctors’ brains consider them meaningless and they tune out.
The sociologist P.M. Strong pointed out a long time ago that most people are actually caught in a double bind when they see doctors. Often, their main reason for seeing us is precisely because they are not sure if they or their children’s experiences fit the patterns of illness that we know about. Yet we doctors get wary if they recite perfect accounts in case they have read them off the internet, and we react with mild contempt when they talk about things we do not understand, like yellow noses.
Social scientists are trained to be more tolerant than doctors. They would take it for granted that the mother genuinely did see her son’s nose go yellow each time that he was about to throw up. They would not be troubled by the fact that her notion of yellow did not correspond with my concept of jaundice. They would also be vastly more curious about exploring the beliefs and explanations that enabled her to notice when noses turn yellow. In other words, they would put her perceptions on a level playing field with mine.
What would happen if doctors did this too? One of the books that most influenced me as a medical undergraduate – as it did many other people at the time – was Thomas Kuhn’s The Structure of Scientific Revolutions. Kuhn argued against the common idea that advances in scientific theory came about as a result of systematic attempts to prove a previous theory wrong. Instead, he proposed a more sociological view. It was one that focused on how people in each generation develop perceptions of the world that do not fit with previous descriptions. Kuhn examined how people generally discount such perceptions at first, assuming that they must be distorted or incorrect because they do not fit with existing theory. Over time, however, more and more people share these perceptions, until they become the nodes around which a new world view starts to coalesce. Once this happens, the old theory simply crumbles away. At first it becomes outmoded, then obsolete, and in time quite incomprehensible.
The best demonstration I know of this process in action appears in an essay about the history of asthma by another sociologist, John Gabbay. He goes through accounts of asthma from the seventeenth century to the twentieth, noting how the shifts from one paradigm to the next are not small evolutionary ones but gigantic philosophical ones. Not only does the knowledge change with each version of asthma, but so does the fundamental nature of that knowledge.
Gabbay points out the temptation to assume that earlier descriptions of asthma will automatically map on to modern descriptions of asthma, or at the very least on to other recognisable conditions like heart failure or cirrhosis. It seems that nothing could be further from the truth. Seventeenth-century asthma does not correspond in any way with modern asthma, but unfortunately it does not remotely correspond with anything else either. People with earlier models of asthma not only believed things we do not believe, but (as Gabbay illustrates in great detail) they saw things we cannot see, used treatments we cannot understand, noticed improvements we cannot believe, and offered explanations that are now totally impossible to follow. Each successive historical version of asthma consisted of a self-referential loop of symptoms, signs, diagnosis and treatment. None of its elements now makes sense to us, or corresponds to anything that can be found in subsequent versions of asthma. The same, Gabbay strongly implies, will eventually be true of our ‘asthma’ too.
Doctors often find this kind of thinking hard to accept. They believe that twenty-first-century knowledge must be in some way entirely different from all previous types of knowledge. They find it hard to accept that even such fundamental notions as anatomy and evidence may one day be replaced by other constructions that we are incapable of even dreaming about. Many sociologists see this limitation in our thinking as simple defensiveness. They would argue that we are locked into our own mindsets first by self-selection as a profession and then by continuing indoctrination. We all feel threatened by the idea that our whole system of scientific belief will one day dissolve. Yet if Gabbay is right, that dissolution is inevitable. And if Kuhn is right, the next medical paradigm may well depend on someone taking yellow noses seriously.