When we need to think about something, working memory in our brain plays a crucial role. In this post, I am going to share five important facts about working memory that I learned by reading a book “Why don’t students like school?” by Daniel T. Willingham (2009).

  1. Working Memory is where Thinking happens

Working Memory is where “thinking” happens. You get information from the environment, and think and try to make sense of it by integrating this new information with the background knowledge retrieved from your long-term memory.  Working memory is consciousness and awareness. There are so many things happening in the environment around you such as a fan making noise or cars going by, but unless you pay attention to it; become aware of it, that information does not enter working memory, so you do not think about it (1).

  1. The capacity of working memory is limited.

Compared to long-term memory, which is vast in capacity, working memory has limited capacity. That is why, when you are working on a complex math problem, you need to write down the steps because you cannot hold all the steps in your head: in your working memory. While you are listening to a book on your iPhone, if some thoughts come to your mind (working memory), you lose track of the author’s thought and have to go back to the point where you were paying attention. That is the reason that working memory is called “bottleneck” of our cognitive system (1).

  1. The bigger your working memory is, the better thinker you are.

Willingham says that there is a correlation between the size of working memory and reasoning ability. According to him, working memory is usually tested by exercises that require simple mental work. For example, you listen to a mixture of letters and digits (for example, 6Q2T5U) and are asked to recite back the digits followed by the letters in order (that is, 256QTU).

Reasoning is tested sometimes with standard IQ tests or “tests more specifically focused on reasoning, with problems like ‘If P is true, then Q is true. Q is not true.What, if anything, follows?’ (2).”

Research shows that the bigger your working memory is, the better your reasoning is, that is, the better thinker you are (1).

  1. You cannot really increase the capacity of your working memory.

You might think then that we should give students exercises to make the working memory capacity bigger. Unfortunately, your working memory is pretty much set; “you get what you get (3).” There aren’t any exercises that make the capacity of your working memory bigger (1).

  1. But there are ways to cheat that limit!

However, you can shrink the content of what you have in your working memory. 

One way to do this is via “chunking.” As I wrote in another blog post, you can organize many individual knowledge elements in working memory into a single knowledge element by the process called “chunking.”

For example, what if you are asked to read the following list of letters and see how many letters you can remember.


It is probably pretty hard to remember all the letters. However, how about the following list?


Even though the first and second lists are the same, the second one is much easier to recall than the first one. It is because you are able to organize those letters into small “chunks” based on the factual knowledge you have in your long-term memory and shrink the content that uses working memory (4).

Another way to shrink the content in working memory is via automaticity; You automate procedures. As I wrote in another blog post, when you started learning to drive, you had to think about each step you took; changing lanes, turning, accelerating. You needed to be conscious for each step and the driving process required a lot of space in working memory. But once you mastered the skill, driving became pretty automatic. You do not need to be conscious about driving and the process requires pretty much no space in working memory. Therefore, while driving, you can add more activities that require you to be conscious such as talking to passengers or trying to understand news on the radio. You can do that since you gained extra space in working memory by automating the driving process. 

These examples show that even though you cannot increase the capacity in working memory, you can gain extra space there by shrinking the content through chunking and automation (1). 

To sum up, all of our thinking happens in our working memory. The bigger your working memory is, the better thinker you are. Unfortunately, the capacity of working memory is pretty limited and there is no way to increase its capacity. However, you can cheat the limitation by shrinking the content in working memory: chunking and automaticity.


  1. Willingham, D. T. (2009). Why don’t students like school?  San Francisco, Jossey-Bass. 81-95. 
  2. Willingham, D. T. (2009). Why don’t students like school?  San Francisco, Jossey-Bass. 95. 
  3. Willingham, D. T. (2009). Why don’t students like school?  San Francisco, Jossey-Bass. 83. 
  4. Willingham, D. T. (2009). Why don’t students like school?  San Francisco, Jossey-Bass. 25-26.

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