Overloading on cognitive load theory in SLA

This is a response to a John Sweller article in 2017 on applying cognitive load theory to language teaching.

Geary and the interface hypothesis

I want to first discuss cognitive developmental and evolutionary psychologist David Geary’s, 2007,  two types of knowledge since Sweller invokes Geary to assert a critical division or discontinuity between child first language acquisition and adult second language acquisition.

Geary’s first type of knowledge (or abilities/domains/cognition, Geary uses these terms interchangeably) has evolved over human evolutionary time and is labelled primary knowledge. Such knowledge (such as your first language) is said to be fast and implicit. Geary’s second type of knowledge develops due to cultural reasons and is slower and explicit. Geary uses reading as an example of secondary type of knowledge. I have dropped the label biological as I think it is unhelpful for the present discussion.

We could see a parallel here between Geary’s division and the conscious/unconscious or explicit/implicit division discussed in second language acquisition (SLA). The following quotes of Geary:

“I focus on primary abilities because these are the foundation for the construction of secondary abilities through formal education.” Geary, 2007:3
“Academic learning involves the modification of primary abilities…” Geary, 2007:5
“I assume that primary knowledge and abilities provide the foundation for academic learning.” Geary, 2007:6

seem to indicate when applied to language that there is some sort of interface between conscious learning of language and its unconscious acquisition.

So does such an interface exist? If so how does it work? Absent answers to such questions we should accept the default position that there is no interface, that explicit conscious language knowledge is separate from implicit unconscious knowledge (John Truscott, 2015).

Discontinuities and the nature of language

Cognitive scientists such as Susan Carey (2009) class language as a core cognitive activity (core cognition differs from sensory-perceptual systems and theoretical conceptual knowledge) along with object, number, and agent cognition. And there is (largely) a continuity of such core cognitions from childhood to adulthood. Discontinuities happen with say object knowledge and physics knowledge – infants know that objects are solid yet when older the theory of physics tells them that objects are not really solid. Here the physics is “incommensurate” with object cognition and this contributes to the difficulty for students of studying physics at school. Physics is at the same time more expressively powerful than object cognition.

It is unclear from Geary what kind of discontinuity is being described or even if there is one (as the labels primary and secondary seem to point to). From what I can gather Geary seems to think that primary knowledge can help with secondary knowledge (seen as the interface position in SLA) and so the two may not be so conflictual after all. I may of course be mistaken in my reading here of Geary.

The unclarity from Geary of what kind of discontinuity he means may explain the logical leap that Sweller seems to have made, namely, adult second language acquisition is secondary knowledge and incommensurate with the child’s first language acquisition. Let’s look at the passage where he indicates this:

“Learning a second language as an adult provides an example of secondary knowledge acquisition as do most of the topics covered in educational institutions. We invented education to deal with biologically secondary information. Learning to listen to and speak a second language as an adult requires conscious effort on the part of the learner and explicit instruction on the part of instructors. Little will be learned solely by immersion. Furthermore, since learning to read and write are biologically secondary because we have not evolved to acquire these skills, they also require conscious effort by learners and explicit teaching by instructors, irrespective of whether we are dealing with a native or second language.”

Sweller seems to be mixing up literacy skills with (adult) language acquisition. And further seems to switch between the two – compare “learning to listen to and speak a second language as an adult requires conscious effort” and “learning to read and write are biologically secondary”. Also he assumes that because languages are taught in schools that means they are like other school subjects i.e. language is like developing conceptual knowledge in physics, maths, chemistry etc.

This assumption that language is like conceptual knowledge is very evident in this 1998 article by Graham Cooper and his use of a “foreign language” example to explain an aspect of cognitive load theory:

Graham Cooper “foreign language” and element interactivity

Most language teachers will find this view of language very peculiar. For example, the assumption that because a vocab item may be a single word it can be classed as a low element interaction. This ignores the semantics of single words for a start. More generally, as seen in the screenshot, there is an assumption that language is an object that can be transmitted to learners from the environment much like concepts in a subject like maths.

Ignoring SLA

I want to now comment on some more paragraphs in the Tesol Ontario article. Let’s start with the first paragraph:

“Most second language teaching recommendations place a considerable emphasis on “naturalistic” procedures such as immersion within a second language environment. Immersion means exposing learners to the second language in many of their daily activities, including other educational activities ostensibly unrelated to learning the second language.”

I guess by “naturalistic” procedures Sweller may be alluding to the Natural approach by Krashen and Terrell? If so he has badly understood what that means and is badly out of date with the debate. Badly understood since the natural approach does not entail immersion and badly out of date by ignoring developments such as task based learning which arguably “includes other educational activities ostensibly unrelated to the second language”.

“Information-store principle. In order to function, we must store immeasurably large amounts of information in long-term memory. The difference between people who are more as opposed to less competent in any area including competence in a second language is heavily determined by the amount of knowledge held in long-term memory (Ericsson & Charness, 1994; Nandagopal & Ericsson, 2012).”

This may, with caveats, apply to vocabulary learning or pragmatics, but how applicable is it to other language systems such as syntax or phonology. Further the studies quoted are based on novice and experts in non-language domains like chess.

“In second language learning, this means teachers should explicitly present the grammar and vocabulary of the second language rather than expecting learners to induce the information themselves (see Kirschner et al., 2006, for alternative formulations that emphasise implicit learning) as occurs when dealing with a biologically primary task such as learning a native language as a child.”

Sweller is characterizing child acquisition as “expecting learners to induce the information”. What is meant by induction here? Does he mean usage based notions of induction where statistical information in the environment is used by the child to learn a language? If so then usage folks say the same process also happens in adult language learning and further that process is not explicit in the sense used by Sweller.

“Requiring learners to go to a separate dictionary imposes an additional cognitive load. Learners should not be required to search for needed information.”

How does this claim compare with say the involvement load hypothesis of Batia Laufer and Jan Hulstijn from 2001, where “search” is one of the cognitive components and more “search” e.g. consulting a dictionary is said to lead to better vocabulary retention? (as an aside – involvement load hypothesis was influenced by the levels of processing theory, a general critique of cognitive load theory is why should more load lead to learning problems? Contrast this to levels of processing which implies deeper (more load?) processing would lead to better performance).

“Another recommendation is to avoid redundancy. Unnecessary information frequently is processed with learners only finding after the event that they did not need to process the additional information in order to learn.”

Considering the reported benefits for novice language learners of elaborated input (not translations but “redundancy and clearer signaling of thematic structure in the form of examples, paraphrases and repetition of original information, and synonyms and definitions of low-frequency words” – Sun-Young Oh, 2001), what evidence is there that such elaborated input is not as beneficial for more expert language learners?

To conclude, note that the summary report from the Centre for Education Statistics and Evaluation (2017) which ELT Research Bites covered, describes several criticisms of cognitive load theory in general. My discussion attempted to critique the application of this theory to language acquisition. This critique is only very cursory but it is I think enough to raise serious doubts about the extent of Sweller’s awareness of SLA research and hence to take any applications very critically. This does not preclude future applications of cognitive load theory in language teaching and certainly, notwithstanding the general critiques, it is applicable in the domain of instructional design where it originated.

Thanks for reading.


Carey, S. (2009). The origin of concepts. Oxford University Press.

Centre for Education Statistics and Evaluation. (August, 2017). Cognitive load theory: Research that teachers really need to understand. Downloaded from https://www.cese.nsw.gov.au/publications-filter/cognitive-load-theory-research-that-teachers-really-need-to-understand.

Cooper, G. (December 1998). Research into Cognitive Load Theory and Instructional Design at UNSW. Retrieved from https://web.archive.org/web/20191020161006/http://dwb4.unl.edu/Diss/Cooper/UNSW.htm

Geary, D. C. (2007). Educating the evolved mind: Conceptual foundations for an evolutionary educational psychology. In J. S. Carlson & J. R. Levin (Eds.), Educating the evolved mind: Conceptual foundations for an evolutionary educational psychology (pp. 1–99). Greenwich: Information Age. Retrieved from https://www.researchgate.net/publication/242124970_Conceptual_Foundations_for_an_Evolutionary_Educational_Psychology

Laufer, B., & Hulstijn, J. (2001). Incidental vocabulary acquisition in a second language: The construct of task-induced involvement. Applied linguistics, 22(1), 1-26.

OH, S. Y. (2001). Two types of input modification and EFL reading comprehension: Simplification versus elaboration. Tesol Quarterly, 35(1), 69-96.

Sweller, J. (August 2017). Cognitive load theory and teaching English as a second language to adult learners. Contact Magazine, 43(2), 5-9. Retrieved from http://contact.teslontario.org/cognitive-load-theory-esl/.

Truscott, J. (2015). Consciousness and second language learning. Multilingual Matters.