I usually use the concept of Degeneracy, as explained here, in the context of religion, and how the contents of religious traditions tend to gravitate towards what is easy to communicate (in the most general sense of the word 'communicate'). Something similar can happen with medical research, and I think most definitely happens, and has happened, in psychiatry. The trouble is that the brain is unimaginably complex, very nonuniform, very nonlinear, and the reasonably uniform and regular behaviour we see on the surface is due to the myriad mental abstractions each of us builds as we grow and learn to live in the world and society. Faced with the demand to practise 'evidence based medicine' about which I discuss more here, the problem is that what counts as 'evidence' will tend towards 'evidence that is easily tabulated in a spreadsheet', or 'evidence that is easy to measure', 'evidence that is easy to see', and so on. It is from that that I coin the term 'Spreadsheet Driven Medicine':
- Want to assess whether somebody is overweight or underweight: use the BMI. (See the article by Keith Devlin as to what's wrong with that.)
- Want to assess whether Tai Chi is beneficial? Send a few people to a Tai Chi class for six weeks and measure the benefits by way of a 20-question multiple choice questionnaire (e.g. 'rate how good you feel now on a scale of 1 to 10'). Same for meditation, same for Yoga, same for mindfulness.
- Want to assess whether 'Yoga is beneficial'? Assume that all Yoga classes and Yoga teachers teach and practise the same thing, that the students attending a Yoga class are indeed doing Yoga, and many other implicit assumptions that are easy to fall into the trap of.
- Want to assess some aspect of a person's psychological makeup, ask them to rate how they feel on a scale of 1 to 10.
And so it goes on. If people were required to do any of the above properly, the difficulty of doing so would increase by at least an order of magnitude, if not much more. Trying to assess the benefits of e.g. Tai Chi, without a deep understanding of what Tai Chi is, what it is meant to be, whether a particular teacher knows what they are doing, whether that teacher's students understand what that teacher is trying to teach, and so on, is fraught with problems and bound to fail to give valid results. Same with Yoga, Mindfulness, Meditation. Then there is the assumption that Tai Chi is a single, well-defined thing in the sense that a 5mg dose of Olanzapine is a well measured quantity of a well-defined chemical whose action on the brain, at the level of individual neural signals, is well known. The trouble is that Tai Chi, Yoga, Mindfulness, and Meditation, are broad umbrella headings, which are hard to properly understand, hard to teach, hard to learn, yet very easy to misunderstand. And yet we will hear of studies of the 'efficacy of mindfulness' and such. Such studies should be taken with a large pinch of salt, and one should enquire as to precisely what is meant by 'mindfulness' (in the case of studying 'efficacy of mindfulness'), what those who practise it are meant to be doing, what those who try to practise it are actually doing, how to discern the difference, and so on.
If we simply ignore all the above difficulties, then 'evidence based medicine' essentially degenerates into a meaningless exercise in 'spreadsheet driven medicine' instead.