“Evidence Based Medicine” is a movement in crisis according to a recent BMJ article by doctors who want to improve it. Many of the responses to the article call for better statistics, more effectively communicated, and one in particular makes a plea for less but better protocols. One doctor talks about a friend who worked as a sailor in command of a nuclear submarine. He said the crew had to learn and consistently apply a small number of protocols and suggests that doctors should do the same.
There is a confusion at the heart of this comment, and in some of the assumptions behind statistics based medicine.
The confusion is that human beings are just complicated machines.
One way to clear up some of this confusion is to think about the differences between the terms complicated and complex.
Machines can be complicated. Technology can be complicated. Anything which is made up of many, many parts which are connected up can be complicated.
So, aren’t human beings complicated then? Aren’t human beings made up of many, many parts which are connected up?
Yes.
Any living organism has many, many parts which are connected up, but there’s a difference.
Living organisms are complex adaptive systems.
Complex adaptive systems have certain characteristics we don’t see in machines not matter how complicated they are. Here are four of them (there are more!)
- Non-linear connections
- Emergence
- Co-evolution
- Autopoeisis
Non-linear connections
You’ll have heard of the butterfly effect? Where a butterfly flapping its wings in the Amazon can cause a hurricane in another part of the world? What that illustration tells us is that very small changes in the starting condition of a system can cascade to rapidly produce very large changes in the outcome. This is the nature of most of the connections in living organisms
Emergence
Complex adaptive systems continuously behave in unpredictable, novel ways. Emergence is a term from biology which describes novel behaviours which could not have been predicted from an examination of the previous state.
Co-evolution
All living organisms exist within specific environments and because they are “open” ie constantly exchanging materials and energy with their environment, both the organism and the environment are constantly influencing each other, constantly responding to each other, and, in fact, even affecting each others evolution. You cannot fully understand a living organism by isolating it from the environment in which it exists.
Autopoesis
This is a term which means “self making capacity”. Not only can living organisms repair themselves, but they can grow, mature, develop and even replicate themselves.
Yes, all that is pretty complicated. But not in the same way a nuclear submarine is complicated. Advanced technologies might seem as if they are alive, but they aren’t.
If we forget this, we try to engage with living organisms as if they are just complicated machines which can be broken down into separate measurable parts, each of which can be managed by the application of protocols.
Living organisms need to be understood as complex, not complicated.
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