John Sweller Interview 4: Biologically primary and biologically secondary knowledge

This is part of a series of blogs detailing a discussion that I had with John Sweller in mid 2017. See all parts of this series on this page. 

Update: I have now written a book that summarises Cognitive Load Theory in concise and practical terms. John Sweller played a key role in the writing process and has described it as ‘An indispensable guide to Cognitive Load Theory for Teachers'. Find out more here. 

OL: This is a question from Michael Pershan. He’s done a great summary of some of your work online . I’ll have to share with you because it breaks it down a lot of great ways. He’s a maths teacher in New York. He’s got a great blog. He wants to know: ‘Does the distinction between biologically, primary and secondary knowledge produce testable predictions?’

JS: Yeah it does. And we haven’t made nearly enough of that. The main prediction is that – it’s almost a description of the two – you acquire skills differently depending upon whether they’re biologically primary skills or biologically secondary skills. There’s a very clear difference in the way in which you acquire them. We’ve just been talking about explicit instruction and the real reason we had a problem with people insisting you don’t need explicit instruction is precisely because that distinction (between biologically primary and secondary learning pathways) was one they weren’t aware of.

OL: I remember I read of this distinction first in your Story of a Research Program paper. And when I read that distinction I was like, “This makes so much sense.” All those arguments people always making about ‘Yeah, but how did you learn to talk? But how did you learn to walk?’

JS: That’s exactly it! And we learn all those biologically primary things without explicit instruction and not only that, it would be absurd to provide somebody with explicit instruction. If somebody come along to you and said: ‘You want to learn English. This is what you do with your tongue. This is what you do with your lips. This is what you do with your breath. This is what you do with your voice. This is how you speak in English' (Laughs). Well, you know, that’s just silly. But that’s exactly what we do with writing. You’ll say: ‘Okay, want to write the letter a? First you write a circle then you write a line on the right-hand side.' That’s exactly what you do. We don’t do that for speaking. And that’s testable and you can build on it and say: In effect, all of the cognitive load effects are testing precisely that because we’re saying: ‘Okay, if you trying to teach biologically secondary material as though it’s biologically primary, it’s not going to work properly.’

A lot of people, including people working in Cognitive Load Theory, because that distinction came a little later, see the biologically primary-biologically secondary distinction as being some sort of optional extra that you don’t really need. You need it very badly. Until that distinction came along, there was a missing part of the jigsaw puzzle. I knew that, ‘ok people say that you can just learn naturally in the classroom’, but I thought, “Well, yeah but it doesn’t seem to work like that when I run an experiment. I can’t get data for it!” And  then all of a sudden, there was the jigsaw puzzle piece.

This biologically primary/secondary distinction came from David Geary. Once you have realized the distinction between biologically primary and secondary, you then need to look at the cognitive architecture associated with biologically secondary material because that’s the material that’s taught in class. You know, when you were teaching, you’re teaching biologically secondary stuff. And there’s a cognitive architecture associated with that (see this podcast with Andrew Martin for more on this cognitive architecture). And that cognitive architecture, those cognitive processes, are different from the processes that are used when acquiring biologically primary material. We’ve touched on some of those differences in the discussion so far, but beyond that, things like, for example, the limitations of working memory that we have when acquiring novel material, that certainly applies to biologically secondary information. I’m not sure it applies in biologically primary. My guess is that it doesn’t, or if it does apply, it doesn’t apply to the same extent. You can take in a lot more biologically primary information than secondary. You know, Miller’s magical number seven plus or minus two. I don’t know what it would be for somebody who’s learning biologically primary information, but I suspect there’s much more than that. I mean, consider our ability to learn and recognise faces. I don’t know how many pieces of information there are that we take note of when we’re looking at a face, but it’s a lot. And we do it simultaneously. Just… there it is! We recognise people. The same goes with language and with everything else that is biologically primary.

OL: There are two exceptions that I’ve thought of to what we’ve just been talking about. The first is—and I’ve just made this connection— I think that perhaps there are limits to working memory in acquiring some biologically primary skills. The example I can think of in this case is, have you heard of motherese? It’s the simplification of language by mothers in order to make it more comprehensible to their young. So that’s perhaps an example of how there could potentially be limits to working memory (on the part of the baby acquiring language) in the context of biologically primary skills.

JS: Yeah, that may be true but, notwithstanding that, you think of what, even in the simplified form, when a mother is saying to the child: “This is a pussycat.” The child can take all of those sounds in. For example, if you heard somebody, assuming you don’t speak Chinese, if you heard somebody say in Chinese: “This is a pussycat.” All you’re going to hear is a sort of sound modulation and if you are asked to repeat that you couldn’t do it. There’s a huge amount of information there. I suspect even if they can’t speak very well, imagine a young kid whose Mommy says: “This is a pussy cat.” They can imagine that speech in their head even if they haven’t quite got the tongue, lips, etc working to actually say it.

OL: Somehow they get it. That’s actually a perfect segue into the next point that I wanted to talk about. And that is, maybe there is a window of time for this specific biologically primary learning. Because for example, I have learnt Chinese, as an adult.

JS: Oh okay! (laughs)

OL: And in order to produce the sounds correctly, I actually literally had to study mouth positions. So it’s moved out of the realm of primary into the realm of secondary, because I’ve missed that developmental period for that language.

JS: That’s actually correct. Before our interview I talked with you about second language learning with my French colleagues, and that’s exactly the problem. People assume that we learn a second language as an adult in the same way as we do as a child, and immersion as a child works perfectly but we’ve evolved for it to work perfectly as a child. For an adult, learning language is biologically secondary. It’s not biologically primary.

OL: It’s funny isn’t it?  How it can switch category. It’s just amazing.

Note: Post 8 of this series also includes a discussion of biologically primary and secondary knowledge in the context of collaboration.

Next post:

5. Motivation, what's CLT got to do with it?

All posts in this series:

1. Worked Examples – What's the role of students recording their thinking?
2. Can we teach problem solving?
3. What's the difference between the goal-free effect and minimally guided instruction?
4. Biologically primary and biologically secondary knowledge
5. Motivation, what's CLT got to do with it?
6. Productive Failure – Kapur (What does Sweller think about it?)
7. How do we measure cognitive load?
8. Can we teach collaboration?
9. CLT – misconceptions and future directions