academic ticks,  Asides

Reductionism is your friend

Management of Complexity

<management of complexity ->

Plenty of better qualified people than myself have made this point, but it's cropped up a few times in both Twitter and face to face conversations, where 'reductionist' has been used in a generally dismissive way, as if to be identified as such signifies the end of a discussion. So, partly because I want to clarify for myself, and also to get feedback in case I'm missing something, I thought I'd set down my take on reductionism.

In general, I think reductionism is a sound approach. Anyone with a child will know that we are natural reductionists. When your child goes through the 'why?' phase what they want is a sub-explanation to a seemingly simple question ('Why is it cold?'). That nearly all children do this naturally should tell us it's a pretty good knowledge gathering approach. You look for answers to a higher level phenomenon by breaking it down into its constituent parts.

Reductionism works well – all around you are the products of reductionism: that computer you're using could have a sticker on it 'Powered by reductionism'; that book on evolution 'Authored by reductionism'; that medicine that is curing your disease 'Brought to you by reductionism'. 

So why are people so down on reductionism? Dan Dennett puts it well in his book Darwin's Dangerous Idea:

"The term that is most often bandied about in these conflicts, often as a term of abuse, is 'reductionism'… [reductionism is made to look] philistine and heartless, if not downright evil… There are bland and preposterous readings of [a reductionist] claim. According to the bland readings, it is possible (and even desirable) to unify chemistry and physics, biology and chemistry, and yes, even the social sciences and biology… According to the preposterous readings, reductionists want to abandon the principles, theories, vocabulary, laws of the higher-level sciences, in favor of the lower-level terms. A reductionist dream, on such a preposterous reading, might be to write "A Comparison of Keats and Shelley from the Molecular Point of View"… Probably nobody is a reductionist in the preposterous sense and everybody should be a reductionist in the bland sense, so the 'charge' of reductionism is too bland to merit a response"

The problem is that of 'greedy reductionism' as Dennett terms it, whereby too much is claimed, too quickly and overly simplistic explanations are given which miss, or ignore some of the complexity. In reaction to this it seems that sentiment has swung too far the other way and declared all reductionism wrong.

There are also phenomenon that reductionism is not good at explaining, for example chaos theory, and emergence. Some scientists will argue that emergence can still be explained in reductionist terms we just don't have sufficiently complex models, and others that it can't and there are emergent properties that are greater than the sum of the parts. This is a debate worth having and whether different approaches are viable to different phenomenon, but surely the conclusion is not that reductionism never works (we have plenty of evidence to the contrary).

Other people have a general mistrust about reductionism, that it is mechanistic and they want to retain some sense of the whole. This can be a misunderstanding about what reductionism seeks to do, as Dennett suggests. As both Marr and Pylyshyn have argued there are different levels of explanation: if you want to know why I was running down the street you expect a psychological explanation ('I was late for a meeting') not a biological one ('my muscles were contracting causing my legs to move in response to messages from my brain'), or a chemical or physical one.

The concern I have about those who wish to dismiss reductionism in favour of more holistic responses is that it is often a pseudo-explanation or even a dead-end. For centuries the church provided this pseudo-explanation along the lines of 'It's God's will', which effectively means don't look any further. But being good little reductionists, people did look further and we found subsequent explanations at every level we looked. This didn't stop people feeling emotions, producing art or making jokes. So I am always wary when reductionism is rejected but nothing offered in its place other than vague ideas of complexity or emergence (or even mysticism). We've been here before. (There is also a slight implication that reductionism is in some sense 'right wing'. I'm probably naive in this sense, but I simply don't understand this at all.)

I fully concur that reductionism is a) not always the best way to explain things b) may miss some subtlety between the components and c) may not be the correct approach as we look at emergent properties in complex systems. But that doesn't mean it offers nothing, so rather than the rejection of reductionism being an endpoint in an argument ('that's so reductionist!') it should be the start, in that you need to have a good reason why it won't work and what you are replacing it with.


  • Cheryl

    Isn’t this just semantics? Couldn’t the good things you claim here as attributes of reductionism be more confidently ascribed to other terms like analysis or synthesis?

  • PhilGreaney

    Interesting stuff. I think reductionism becomes problematic when it is in direct opposition to some of the things we hold most dear. For example, when asked by our partners why we love them, we might say it’s because we find them kind, or generous in spirit, or unafraid, or open and so on. Much less palatable (but perhaps no less true) is that they represent the ideal of a mate who, given the time and place, we can reproduce our genes with. I understand from recent studies that attraction, for example, is partly based on on pheromones released during breathing – and this, rather than their worldview or love of kittens, is as much a deciding factor. We love our children, too, deeply – but similar psychological imperatives are in play. We are just obeying psychosocial orders.
    By extension, it’s likely that we prefer free will to play a part in our lives rather than simple determinism. (Does compatibilism have something to teach us here about combining reductionism with a grander personal metaphysic? Maybe, like Dubya’s fish and mankind, they can co-exist peacefully.)
    Perhaps the important thing is we are able to adequately assemble and sustain the illusion of a non-reductionist way of thinking. We may know it’s true my partner loves me (or yours loves you) because I look like I’m not going to die before I’ve raised the children: but we sustain the illusion that they love us, of their own free will, because of who I am. Then the question becomes: is it possible or desirable to remove the curtain, Matrix style, and recognise the world for what it is?
    What this shows is that our ways of thinking and understanding the world are inextricably linked to our ego, subjectivism, our need for mystery, as we suspected.

  • Martyn Cooper

    Reductionism has more than one meaning in different contexts. The aspect that gives me concern is the approach in some parts of some sciences (e.g. psychology, medicine, neurology) that tries to determine what is the impact of a given property on the phenomenon in question by controlling out all other envisaged variables. This approach is often flawed because of the complexity of systems – the interdependence of the variables and their combined effects on the phenomenon.
    It is an oft stated “fact” that the human brain is the most complex thing yet discovered in the universe. Whatever the truth of that it is highly complex and its neural connections embed a huge degree of parallelism. Much emphasis in brain sciences has been on locating areas of the brain seen as responsible for different functions. IMHO (as a systems engineer not a neurologist) this has been to the neglect of the parallel systems nature of the brain and the emergent properties that are characteristic of such systems.
    In psychology especially cognition I think that J. J. Gibson spoke well to this issue in his work under the term Ecological Psychology. In this he encourages the human to be viewed as a system in relation to its environment.
    Now what is the relevance of this in a blog about Ed Tech? Firstly our current understanding of the brain and cognition are still very limited. I believe that this also implies that our models of learning are also very limited. We only have a vague notion of how memory works and the connection between the external world and how memories and understanding are constructed is less understood. When we now consider how technology is used to mediate “learning experiences” a further degree of complexity and limited understanding is introduce into the problem domain.
    Now all this goes to make educational technology an exciting area of study. But it is one in which we are groping at the boundaries of many areas of current scientific understanding. Hence humility is called for in all our findings. If we “reduce” our research to investigating tiny little aspects of teaching and learning with technology; we will be a victim of “reductionism” in limiting the insights of our research.

  • Dominik Lukeš

    The problem with this view is the well known quote (can’t find who said it now) that ‘we tend to be reductionist about other people’s fields of inquiry and reactionary about our own.’ I suspect that if you examine your own blog you’ll find yourself railing about other people’s reductionism of digital scholarship.
    Reductionism is a necessary individually cognitive mechanism but can be a really evil mechanism when amplified through social cognition. I’m doing research on metaphors in the discourse on education and it has led me to propose a radical non-reductionism: No matter how strong a similarity or perceived causal connection between two levels of magnification of a particular phenomenon, the explanation of what goes on on one level can never be exhaustively formulated in terms of what we see on another level of magnification. For instance, you can’t explain the solidity of walls just by looking at particles, you can’t explain evolution of organisms just by looking at genes and you can’t explain shared knowledge just by looking at the psychology of individuals.
    Of course, reductionism itself is both an individual and social phenomenon. See for example: “For centuries the church provided this pseudo-explanation along the lines of ‘It’s God’s will’, which effectively means don’t look any further.” which is problematic at two levels:
    1. It’s a historical reductionism: From a certain level of magnification it appears accurate but at a more finegrained level to turns out not to be the case (e.g. even the Inquisition was much less blind to problems with testimony obtained by torture than modern portrayals indicate; and it inherited its methods-which were put into practice by secular authorities-from the ‘enlightened’ Romans).
    2. It ignores the fact that present discourse is full of reductionism to evolution or genetics that are no more explanatory than the reductionism to God’s will.
    Dennett’s own bland/preposterous division sweeps too much under the carpet. See for instance E O Wilson’s “Consilience” which styles itself as bland reductionism but is probably more preposterous. The prestige of certain fields makes us much more ready to accept preposterous reductionism as bland – as the Sokal Hoax revealed. The insistence of randomized-control methodologies for evidence to underpin education policy is another example.
    I agree with the criticism of the holistic response. Reducing to the general is just as bad as reducing to the particular. My proposal is to always describe phenomena on their own terms. It is acceptable to use terms and methods from other levels of description but only heuristically and never hermeneutically.

  • Martin

    @Martyn I agree – and that is what I was trying to get at with levels of explanation. There is a difference though between whether it is useful to explain something in reductionist terms (it often isn’t) and whether it is possible. If it isn’t possible is that because we don’t have sufficiently complex models or is it that we could never have the right ones because ‘something else’ is going on? My interest was why so often do I hear ‘oh that’s a reductionist argument’, where the person means ‘we all know reductionism is wrong so I don’t need to argue my case any further’. So really this was a defence of reductionism from this dismissive attitude. I think it’s ok to reject reductionism in some cases as not appropriate, but I think you need a good explanation as to what you’re replacing it with (a systemic perspective might be one such answer).
    @Luke – I’m not convinced. I’m not sure if you’re not falling into the trap of labelling everything reductionist and therefore dismissing it. I don’t think it is historical reductionism to say that religion generally offers a pseudo-explanation, in part that’s what it is there for, to offer explanations that are beyond this world. The reductionism to genetics or evolution is far more sophisticated than you give it credit for here – it acknowledges the complexity of interactions both between genes and the environment. It is only popular (mis)interpretations that insist we have found the gene for behaviour X. But if we are not a product of our genes and our environment then ultimately what are we? It may be impossibly complex to ever reduce, and ultimately not appropriate to describe human and social behaviour in these terms (like Dennett’s poem) but that doesn’t mean that those aren’t the processes in operation.

  • Paul Crowley

    Dawkins makes a similar point in The Blind Watchmaker:To call oneself a reductionist will sound, in some circles, a bit like admitting to eating babies. But, just as nobody actually eats babies, so nobody is really a reductionist in any sense worth being against. The nonexistent reductionist – the sort that everybody is against, but who exists only in their imaginations – tries to explain complicated things directly in terms of the smallest parts, even, in some extreme versions of the myth, as the sum of the parts! The hierarchical reductionist, on the other hand, explains a complex entity at any particular level in the hierarchy of organization, in terms of entities only one level down the hierarchy; entities which, themselves, are likely to be complex enough to need further reducing to their own component parts; and so on. It goes without saying – though the mythical, baby-eating reductionist is reputed to deny this – that the kinds of explanations which are suitable at high levels in the hierarchy are quite different from the kinds of explanations which are suitable at lower levels. This was the point of explaining cars in terms of carburettors rather than quarks.

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