Talking Trees and Talking Humans: why human cognition is not a natural information processing system

John and Susan Sweller argue that Human Cognition is a Natural Information Processing System.[1] I have many problems with this view, but in this post, I want to highlight a particular mistake in their thinking: the conflation of one-way powers with two-way powers. 

Firstly, I shall use the idea that trees talk to each other to explain the distinction between the two kinds of powers. Secondly, I shall show how they become conflated. Thirdly, I shall then show how conceiving of human cognition as a natural information processing system is an example of such a conflation. 

I. Can trees talk to each other?: One and two-way powers.

According to this article, trees communicate with each other via ‘underground fungal networks’; they support each other and help each other grow by sending chemical and electrical signals to each other.[2]

It’s a fascinating article and there’s something wonderful about the idea of envisaging trees in this way. On the other hand, it is also quite clear that the sense in which trees talk to each other is quite different to the sense in which humans talk to each other. We might be tempted to just think that it’s a matter of a different language, and that eventually, we will be able to translate this language of trees into our own language. Whilst I am all for communing more with trees and nature, I think that we need to be careful with where we go with this idea. As concepts (in this case talking and communication) are stretched to fit ever more inappropriate situations, we are in danger of degrading them.

The reason we might think that it makes sense to say that trees talk to each other is because they send signals to each other. Superficially this makes sense: 

  1. to talk is to communicate
  2. to communicate is to send signals
  3. trees send signals
  4. ∴ trees communicate
  5. ∴ trees talk

We can of course pick holes in (1) and (2) but it is (3) which seems to me to be the crucial premise here. What sorts of things have the power to send signals or messages? Well I could say that the trees send the signal to me that autumn has arrived when their leaves change colour; or I could say that my wife sent me a signal that it was ok to come in by waving her hand. So, on first glance, it seems as if trees can send signals, just like my wife – but there are obvious differences here. The tree is not sending me the signal intentionally. It would not make sense for me to berate a tree for not having warned me of the change of seasons. (Although Jesus did weirdly have a go at a tree for not bearing fruit – but that’s a topic for another post.) The tree, or rather the leaf has no choice but to change colour. Peter Hacker calls this a one-way power[3]. If the conditions are right for the leaf to turn brown, it will turn brown. There is no such thing as a leaf refraining from turning brown.[4] My wife, on the other hand, has a two-way power to send me a signal – she has a choice. And because she has a choice, it makes sense to say that she acts intentionally, voluntarily.

II. The danger of conflating one and two-way powers.

There is a danger here that we might conflate the one-way power of communication that we have ascribed to trees with the two-way power of communication that we can ascribe to humans. If we conflate the two, we will find ourselves going down one of two routes: Either we will conclude that the ability to communicate is always a two-way power, and that since trees can communicate, we can sensibly imbue them with an ability to choose, to refrain from doing things should they wish, or we conclude that the power to communicate is always a one-way power.

The first route seems less dangerous to me. I’ve always been attracted to animistic worldviews. There has been a tendency (in Eurocentric science) to see such views as primitive but, as we struggle with ecological disaster, the wisdom of such positions comes to light. There are countless examples of ancient wisdom proving more robust and valuable than the hubris of the ‘enlightened’ scientific outlook which conceived as humans as the masters of nature, their power justified by all their ‘knowledge’: the tragedy of the buffalo on the plains; the destruction of the Amazon rainforest; the bushfires in Australia. That said, there are limits to how far we can stretch this view. There is not space to go into it here, but a shared language requires a shared form-of-life, hence why, as Wittgenstein wrote, ‘if a lion could speak, we could not understand him’.[5] How much less we have in common with trees.

The latter conclusion, that the ability to communicate is always a one-way power, is the most common in my culture and the cause of a great deal of confusion. The confusion occurs because in ordinary language, the power to communicate is essentially, necessarily a two-way power: Communication is concerned with meaning and to be able to mean something with our utterances or behaviour is to have a two-way power. To mean something is to intend to convey something, to do so voluntarily. If we don’t have the ability to not utter something or behave in a particular way (i.e. if we only have a one-way power) then we cannot mean anything with what we do.

(This confusion is knotty, however. We can even see this one/two-way power distinction with the verb mean: compare ‘the heavy blizzard meant there would be no school’ with ‘I didn’t mean to upset you’. The former sense merely means to have as a consequence, whereas the latter sense means to intend to convey. My harsh words might mean that he left, but that doesn’t mean that I meant to make him to leave.)

III. The conflation of one and two-way powers in education research

In a great deal of education research, we see the power to communicate reduced to a one-way power – consider how Sweller et al conceive of human cognition as a natural information processing system, comparing it with evolution. It should be clear by now, that evolution (as conceived by Sweller et al.) will only possess one-way powers. Evolution, like a tree, cannot intend to do anything, and as a result it makes no sense to blame, be angry with or punish evolution (except perhaps poetically). As a result, concepts like communication, language, information and knowledge, come mean something quite different to what we refer to in ordinary language. All the meaning is removed from their account and replaced with mere consequences. (It is not difficult to see how this might have grave consequences for how we conceive of education.)

Let’s take, for example, the concept of information in natural information processing system. We might think that we can define information here as data. Although we might now imagine a series of 1s and 0s or statistical data, that doesn’t really clear anything up. Without the sense of intention, we still have no means of distinguishing between data/information and mere noise.

In his paper, A Mathematical Theory of Communication, Claude Shannon came up with an ingenious distinction between noise an information in terms of how likely the signal was to occur, so the amount of information contained within a signal is inversely proportional to the probability that it occurred[6]. The less likely it was to occur, the more information it contained. Mathematically, he expressed this as I(x)=-log2p(x), where x is a discrete random variable, and I(x) is the amount of information contained in x and p(x) is the probability of x occurring. Shannon’s sense of information became ubiquitous with the rise of computers, and is clearly the ancestor of the sense of information that Sweller et al have in mind (although I’ve never seen them say anything like, ‘the amount of -log2p(x) in the long-term memory’, so I am still unsure as to whether even this clarification would make their view coherent).

It should be clear, that this definition of information bears little relation to the everyday concept that we are referring to when we say, ‘all the information that you need is on the sheet’, for example. Shannon had set out to find a way to solve engineering problems involving communication over a noisy channel. He did not set out to deal with questions of meaning or interpretation, which his theory, in his words, ‘can’t and wasn’t intended to address’. The power to transmit or receive Shannon-information is always a one-way power; the power to communicate or receive information (in an ordinary sense) can be a two-way power – it can be done so with intention and meaning.

IV. Conclusion

As I have said at the beginning, I have no problem with people using words how they want, and sometimes these stretched or metaphorical uses can be beautiful, and in other cases they can be useful. But we must be aware of what we are doing, what concepts we are conflating, lest we create confuse these metaphorical uses with the ordinary uses and create an abomination. And perhaps, if we are in doubt, it’s safer to imbue something intention rather than not!

[1] John Sweller and Susan Sweller, ‘Natural Information Processing Systems’, Evolutionary Psychology, 4.1 (2006), 147470490600400 <;.


[3] P. M. S. Hacker, Human Nature: The Categorical Framework (Oxford: Wiley-Blackwell, 2010). p.95

[4] One could argue that I am indulging in a mereological confusion here – the leaf may have no choice to turn brown, just as my finger may have no choice to extend, but perhaps the tree has a choice as to whether it sends me a signal, just as I have a choice as to whether I point. All that this shows, however, is that the prototype of sending a signal is human and intentional, and that it has at some point been applied to trees metaphorically.

[5] Ludwig Wittgenstein, Philosophical Investigations.The Philosophical Quarterly, 1967, xvii <;.p.223

[6] C. E. Shannon, ‘A Mathematical Theory of Communication’, Bell System Technical Journal, 27.4 (1948), 623–56 <;. See also M. R. Bennett and P. M. S. Hacker, ‘On Explaining and Understanding Cognitive Behaviour’, Australian Journal of Psychology, 67.4 (2015), 241–50 <;.

2 thoughts on “Talking Trees and Talking Humans: why human cognition is not a natural information processing system”

  1. hi
    Bruner in 1990 Acts of Meaning pg4 –
    “Very early on [in the cognitive revolution], for example, emphasis began shifting from ‘meaning’ to ‘information’, from the construction of meaning to the processing of information. These are profoundly different matters. The key factor in the shift was the introduction of computation as the ruling metaphor and of computability as a necessary criterion of a good theoretical model”

    so if proponents of natural information processing systems were more honest they would start calling it natural computation : )

    Liked by 1 person

    1. Brilliant, thank you so much for that! I’ll definitely put that on my list of things to read. I think that this is so crucial. The confusions are so deep (and I think important) but so many people seem to be utterly oblivious to it!


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