What is Critical Thinking? An example from the Cognitive Approach.

Your teacher sets you an essay: Discuss one or more models of a cognitive process.

You approach this first psychology essay with enthusiasm and write absolutely all you know about the multi-store model of memory and use a study to show how good it is as an explanation for the fact that short-term memory and long-term memory are separate stores. But when your essay comes back you are very disappointed with your mark and don’t understand how after all your work and everything you knew you did so badly.

Your teacher says there was no critical thinking in your essay. In fact, they have written ‘So what?’ in the margins of the essay at regular intervals. You have ‘described’, not ‘discussed.’ Discussing a model or theory requires you to ask yourself the ‘so what’ question; to wonder.

When they say that your work lacks critical thinking what do you think this means?  Do you think it means that you haven’t criticised the study or theory enough? Or that it means that you have just been descriptive, without really thinking at all? While there is an element of truth in each of these, what a lack of critical thinking means is that you haven’t wondered enough – about the theory, the methodology, the findings, and the conclusions. What do they really show? How do they relate to the question? And you haven’t supported your wondering with evidence from psychologists who have also wondered.

Here is an example of what you could have done.

Try to identify exactly where the critical thinking is. (Remember, this is just part of the body – you would need to give a few more details of studies and add an introduction and conclusion.)

The multi-store model of memory was developed by Atkinson and Shiffrin in 1968. They theorised that memory is organised in a linear fashion into three separate stores: a fleeting sensory memory for information from our five senses; short-term memory, which receives the sensory information to which we pay attention; and long-term memory, to which the encoded information from the limited-capacity short-term memory will pass, providing we have either rehearsed it or organised it in a meaningful fashion. Long-term memory is where we store all our permanent memories, of our childhood experiences, our learned skills and the knowledge that helps us plan and predict our lives. Some of this will be explicit, like our memory for events, and some will be implicit, such as our unconscious memory of how to do things. Research by Glanzer and Cunitz (1966) used their serial position effect experiments to show that short-term and long-term memory seem to be separate. Words at the beginning of a list were stored in long-term memory (primacy effect) and those at the end of the list were stored in short-term memory (recency effect). As expected, interference preventing rehearsal interfered with the recency effect, as the words decayed from short-term memory. This suggested, even before Atkinson and Shiffrin fully developed their model, that these were separate stores.

However, the multi-store memory model argues that only sensory information to which we pay attention will pass to short-term memory and consciousness. But research into sensory memory, trauma and PTSD has shown that unprocessed sensory information can create discomfort and stress, even if this cannot be voiced as it is something of which the person is not fully conscious (Nursey & Phelps, 2016). This raises the question of where this information is stored in the multi-store model, if attention is needed to pass it into the short-term memory.

Another issue is with the image of short-term memory as a very limited store, argued by Miller (1956) to only hold about seven pieces of information (+/-2) for up to thirty seconds before it decays or is displaced by incoming sensory information. This suggests it is a kind of ‘holding bay’ for information on the way to long-term memory and has no processing function. However, Baddeley and Hitch (1974) proposed that short-term memory is a system with many working components that processed visual and auditory data separately, allowing for multi-tasking, and then also together for an integrated understanding. This meaningful information is then passed into the long-term memory. This undermines the idea of the short-term memory as a mere device to hold information until it is able to be passed on to the long-term memory.

Finally, the linearity of the multi-store model has been called into question by the research of Shallice and Warrington (1970). Their participant, K.F., had been injured in a motorcycle accident and this had badly affected his short-term memory. However, he was able to make long-term memories and his performance on long-term memory tasks was normal. This suggests that short-term and long-term memory operate in a parallel fashion, rather than sequentially.

Learn how to think critically, and enjoy the different comments you get on your essay!


Baddeley, A. D., & Hitch, G. J. (1974). Working Memory. In G. A. Bower (Ed.), Recent Advances in Learning and Motivation (Vol. 8, pp. 47-89). New York: Academic Press. http://dx.doi.org/10.1016/s0079-7421(08)60452-1

Glanzer, M., & Cunitz, A. R. (1966). Two storage mechanisms in free recall. Journal of Verbal Learning & Verbal Behavior, 5(4), 351–360. https://doi.org/10.1016/S0022-5371(66)80044-0

Miller, G. A. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological Review, 63(2), 81–97. https://doi.org/10.1037/h0043158

Nursey, J. and Phelps, A.J. (2016). Chapter 20 – stress, trauma, and memory in PTSD. In: Fink, G. (Ed.), Stress: concepts, cognition, emotion, and behavior. San Diego: Academic Press, 169–176.

T. Shallice, T. & Warrington, E.K. (1970). Independent functioning of verbal memory stores: A neuropsychological study, Quarterly Journal of Experimental Psychology, 22(2): 261-273, DOI: 10.1080/00335557043000203