Complexity Chaos and All That Jazz - John Watkins
Summary of a talk given in Cardiff 13th June 2012
The basis of this talk is to bring together some of the underlying principles
surrounding the emerging field of complexity. I will seek to define and develop
ideas surround the terms chaos, and complexity and show how a greater
understanding of these can lead to a better approach to health and
healthcare.
The macroscopic complex nature and beauty we see in snowflakes, flows
naturally out of the interplay between the underling structure of solid ice and
the transition that water undergoes as it passes from the liquid to solid state.
One might ask what this has to do with complexity, but all will be revealed.
One overwhelming difference between chaos and complexity is that the
former is deterministic, given the right knowledge of the starting conditions of
a system, and the latter which is not, due to inherent randomness built into
complex systems.
The well known ‘manifold’ used to look at the relationship between 3
parameters in a chaotic system, reinforces the image that systems held far
away from equilibrium, e.g. super cooled liquids, some aspects of human
behaviour, etc., can suddenly switch from one state to another, liquid to ice,
stable societies to unstable. These parallels between physical and human
behaviour have often, mainly erroneously, led people to believe that the
reductionist methods of the natural sciences, such as physics, can be used to
focus on very human endeavours, such as economics. Whilst it is true, that
many aspects of our daily lives undergo sudden shifts from chaos to order,
e.g. people walking in corridors, traffic meeting at junctions, traffic jams, this
shift of state, this phase transition, can be unpredictable due to the complexity
inherent in human behaviour. Phase transitions, such as those seen when ice
melts or water boils, or when magnets cool past their critical point, are well
studied in nature, however, when these changes are studied by physicists a
number of assumptions are made.
Physics, by its very nature, is reductionist and most of the states explored by
it are in equilibrium. Physicists assume that the particles in a gas are non
interacting and indistinguishable and so can be grouped together as a whole
system. By contrast, many aspects of our society are interconnected in
complex ways leading to great difficulties in knowing what effects small
perturbations may have. Economics as a discipline has struggled under this
misconception for well over the last 100 years.
Some of the greatest minds in economic theory, for example, have made the
assumption that ‘the market sets the price’ and any perturbations about this
price are purely random, a bit like the Brownian movement of dust particles
suspended in still air. Nothing could be further from the truth, market
fluctuations are the product of the complex interactions of human kind,
interacting in unpredictable ways. One only has to travel down the M4 to
London and experience the ‘phantom’ road block to see that this human
interaction is anything but random.
Detailed examination of the daily fluctuations in the Dow Jones will show that
the financial markets are very different from those predicted by the
randomness of Brownian motion and, at times, undergo tremors almost
indistinguishable from an earthquake’s seismic trace. We can also see that
using standard models to predict complex behaviour, based on the
assumptions of randomness and non interaction, rarely gives an accurate
forecast c.f. the barrel price of oil over the last 20 yrs. The spike in the oil price
in the late 2000’s was not due to a shortage of oil, or social unrest, but driven
by speculators, the coordinated efforts of a small sector of society.
So what is going on? Can we make sense of this?
Rather than systems such as; the world financial markets, healthcare
demand, flooding, cloud formation, earthquakes etc., being due to purely
random fluctuations, they are each in fact complex systems that interact in
ways that are non linear.
To understand what we mean by non-linear we need to dip into the world of
fractals, which is dominated by power laws. The defining feature of power
laws are what physicists call scale free distributions, in which there is no
typical distribution (unlike the binomial/normal distribution) and in such
circumstances, it is not possible to state a mean and standard deviation with
any authority, other than to say that such systems are biased to smaller
events and that large deviations are less likely. These scale free non linear
events can be represented both mathematically and graphically and underpin
much of our understanding of the world we live in e.g. the laws of
electrostatics, gravitation, black body radiation and Pareto’s distribution, well
known to social scientists. In such systems log/log plots will lead to straight
line relationships in which the slope will define the power of the relationship
between two parameters, e.g. size of flood v its probability. Scale invariance
leads to the fractal nature of; second to second, day to day, week to week etc.
variations in water levels, seismic activity, share prices etc.
Systems at the ‘edge of chaos’ do not have the same orderly behaviours of
gases or liquids in equilibrium, which makes predictions uncertain. Complex
systems are generally made up of many parts, with potentially non linear
interactions and interdependence. Complex system exhibit structure over
several scales, the emerging behaviour of which might not be deduced from
examination of the parts, e.g. human behaviour is not predictable by mere
anatomy and physiology alone.
Complex systems are self organising as we have seen from traffic jams,
people in crowded corridors or the beauty of snowflakes. Complex systems
have multiple feedback/control loops with interplays between cooperation and
competition. If we want to understand and shape healthcare we need to
understand and copy the most complex system we know, ourselves.
The human body, with its emergent behaviour that allows us to contemplate
our own existence, employs multiple feedback systems at all levels, we
should accept, that in order to shape healthcare and healthcare demand, we
need to work at all levels and not, unidirectional, from top down.
Its not rocket science it’s much more complex that that!!