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Chaos, Determinism, & Psychology

I’ve been rereading James Gleick’s excellent book Chaos  (1988), and it started me thinking about the practical usefulness of a deterministic psychology.

Determinism in psychology has always been a personal problem for me, because it’s difficult to reconcile the rigid determinism that the science of psychology must lead to: ‘varying factor X will result in effect Y’, with the feeling of free will and choice which is an everyday experience. As a scientist, I have to go with determinism; as an individual, I feel I have free will and I regret the bad choices I continually make. OK, that’s an existential problem, but what about the practical usefulness of a deterministic psychology?

I think understanding chaotic systems and how they work gives us some ideas about this.

Here’s the creation myth of chaos theory: a meteorologist called Lorenz constructed a simple mathematical weather model in 1961 consisting of a dozen non-linear equations. These describe things like the relationship between temperature and atmospheric pressure, and pressure and windspeed. He fed data on these variables into a computer model and let it run to see what weather it would predict. In those days, computers were slow and calculations took a long time to run. On one occasion, he restarted the calculation that he had had to stop partway through by retyping in the figures that the incomplete run had produced.

To give the machine its initial conditions, he typed the numbers straight from the earlier printout. Then he walked down the hall to get away from the noise and drink coffee. When he returned an hour later, he saw something unexpected, something that planted the seed for a new science.

The new run should have exactly duplicated the old. Lorenz had copied the numbers into the machine himself. The program had not changed. Yet as he stared at the new printout, Lorenz saw his weather diverging so rapidly from the pattern of the last run that, within just a few months, all resemblance had disappeared. He looked at one set of numbers, then back at the other, he might as well have chosen to random numbers out of a hat. His first thought was that another vacuum tube had gone bad.

Suddenly he realised the truth. They have been no malfunction. The problem lay in the numbers he had typed. In the computer’s memory, six decimal places were stored: .506127. On the printout, to save space, just three appeared: .506. Lorentz had entered the shorter, rounded off numbers, assuming that the difference – one part in thousand – was inconsequential.
Gleick (1988), p16

But it wasn’t inconsequential. What Lorenz had discovered was that even a tiny change in the starting conditions of a process which depends on several non-linear functions can lead to unpredictable and far-reaching changes in final outcomes. This is what we now call the ‘Butterfly Effect ‘: a tiny change in weather conditions in one part of the world may lead to large unpredictable changes elsewhere. Because of this, it is now generally recognised that long-term weather prediction is practically impossible, no matter how sophisticated our computer models or how extensive and precise measurements of the conditions are.

I think the same applies in psychology. Although we can describe some psychological functions in terms of how factor X leads to effect Y, those functions are generally non-linear. A trivial but obvious example is the effect of amount of alcohol consumed on how good you feel. At low levels, increasing the amount consumed increases the sense of well-being in many people; a higher levels, increasing the amount consumed just leads to the resolution to never, ever, do this again.

Now, if the deterministic relationships which control our behaviour are non-linear, and we are complex systems in which many of these non-linear relationships interact, we are perfect examples of a chaotic system. As such, no matter how well we understand the relationships, nor how precisely we can measure (or control) the starting conditions, we cannot make long-term predictions of the outcomes.

Gleick sums this up later in the book in describing the views of psychiatrist Arnold Mandell:

To Mandell, the discoveries of chaos dictate a shift in clinical approaches to treating psychiatric disorders. By any objective measure, the modern business of ‘psychopharmacology” – the use of drugs to treat everything from anxiety and insomnia to schizophrenia itself – has to be judged a failure. Few patients, if any, are cured. The most violent manifestations of mental illness can be controlled, but with what long-term consequences, no one knows. Mandell offered his colleagues a chilling assessment of the most commonly used drugs. Phenothiazines, prescribed for schizophrenia, make the fundamental disorder worse. Tricyclic antidepressants “increase the rate of mood cycling, leading to long-term increases in numbers of relapsing psychopathological episodes.” And so on. Only lithium has any real medical success, Mandell said, and only for some disorders.

As he saw it, the problem was conceptual. Traditional methods of treating this “most unstable, dynamic, infinite-dimensional machine” were non-linear and reductionist. “The underlying paradigm remains: one gene – one peptide – one enzyme – one neurotransmitter – one receptor – one animal behaviour –  one clinical syndrome – one drug – one clinical rating scale. It dominates almost all research and treatment in psychopharmacology. More than 50 transmitters, thousands of cell types, complex electromagnetic phenomenology, and continuous instability-based autonomous activity at all levels, from proteins to the electroencephalogram – and still the brain is thought of as a chemical point-to-point switchboard.” To someone exposed to the world of non-linear dynamics the response could only be: how naïve. Mandell urged his colleagues to understand the flowing geometries that sustain complex systems like the mind.
Gleick (1998), pp 298-299 (Gleick gives a reference to Mandell’s original writing: I’ve put that at the end).

We might not be quite so pessimistic as Mandell about the effectiveness of psychopharmacology, though even 25 years later I’m not sure that much has changed, and his description of the models used is a bit of a caricature, but the basic point of the unpredictable chaotic nature of the human system is surely valid.

So, even if it were the case that we were completely deterministic systems (like the meteorological systems of weather), and we could determine the relationships within those systems (which we are clearly a very long way away from being able to do at the moment), would that be useless in producing a fully descriptive, fully predictive psychology?

Well, yes and no. We now know that long-term fine-grained meteorological prediction is impossible, but short-term local weather forecasts can still be very useful, even though we don’t expect them to be completely accurate. Similarly (until we started messing around with things with ever-rising CO2 levels, at least) we can make reasonably reliable long-term general predictions. We know how April in Spain will generally differ from August in Spain, and how the weather there will generally differ from the weather in Finland at the same times of year. In many cases, that’s good enough to be going on with, but we are always aware of the possibility of ‘freak’, ‘unpredictable’ weather events.

Similarly, we can make pretty good short-term psychological predictions, certainly in terms of predicting the general outcome of experimental manipulations, and generally useful long-term predictions, based on the climatic differences between ‘introvert’ and ‘extrovert’, or convergent and divergent thinkers.

In fact, in a chaotic deterministic model, failures of prediction, such as the unpredictable extroverted behaviour of some introverts, and people’s ability to switch from convergent to divergent in certain circumstances, might not be disconfirming evidence for our models. Some unpredictability is to be expected. As long as we limit predictions to the very short term or to generalisms, and have some idea of the unpredictability to be expected (which chaos theory can give us), our models may serve pretty well. That is, they can serve understanding of the processes involved, but may be much less useful for control or categorisation. Even in a fully deterministic world, the ‘gene for believing in flying saucers’ is not going to be simplistically effective, and the test for leadership potential is not going to unerringly detect potential leaders.

So where does this leave the effective usefulness of a completely deterministic psychology, and what does it mean for the existential problem of the possible illusion of free will? I think it shows that the aim of describing, understanding and controlling human behaviour through deterministic (and reductionist) models is over-optimistic. We can make some weather-forecaster-like predictions, but more holistic and phenomenological ways of understanding are going to be equally useful. I think the same applies to determinism and free will. It may be that all my thoughts, reactions, and behaviours are determined, but if so, since they are determined in a way which is unpredictable (and may be unfathomable) carrying on behaving as though I have free will and I’m responsible for the choices I make not only seems to work, but might be the most practical alternative. We are aware that we are to some extent determined; we have ideas of internal and external compulsion, but we also have ideas about ways of working with that, and to the extent that these ideas work, they are practically, humanly, useful – even if fundamentally illusory. This is the solution that that old determinist Skinner came to in his book Beyond Freedom and Dignity. Although he felt that behaviour was determined by reinforcement contingencies, somehow, if we have the ability to understand and manipulate those contingencies, we can choose to create better or worse worlds.

In some ways this is similar to the practical solution of the Cartesian problem, that we can never be sure that the world we experience is as it seems to be – that it is not an illusion produced by our senses. It could well be an illusion, but unless someone is offering us the red pill or the blue pill, there is no way of establishing that, and the only sensible thing we can do is to operate in the world as we experience it. What other world could we operate in? Also, we know that some parts of our world experience are illusory, and the understanding of that gives us a more secure basis for operating in good faith in other parts of the world.

Yes I know that’s simplistic, and ignores problems like the false consciousness associated with late-phase capitalism, but it works for me. Just as Samuel Johnson established the existence of the stone by kicking it*, my world of free will is established by the consequences of the good and bad choices I seem to be making, and the pleasure I experience in looking at the trees  and birds which seem to be in front of me.


Gleick, James (1988) Chaos: Making a new science London: Cardina

Mandell, Arnold J. (1985) From Molecular Biological Biological Simplifiaction to more Realistic Central Nervous System Dynamics: an Opinion in Cavenar & al (eds) Psychiatry: Psychobiological Foundations of Clinical Psychiatry New York: Lippincott (cited in Gleick, 1988)

Skinner, B.F. (1971) Beyond Freedom and Dignity NewYork: Knopf

*After we came out of the church, we stood talking for some time together of Bishop Berkeley’s ingenious sophistry to prove the non-existence of matter, and that every thing in the universe is merely ideal. I observed, that though we are satisfied his doctrine is not true, it is impossible to refute it. I never shall forget the alacrity with which Johnson answered, striking his foot with mighty force against a large stone, till he rebounded from it, “I refute it thus.”
— James Boswell In Boswell’s Life of Johnson (1820), Vol. 1, 218.


One response to “Chaos, Determinism, & Psychology

  1. Pingback: Mind? Brain? As a psychologist, who cares? | millerpsych

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