Critical Thinking with Argument Maps

By Dave Kinkead, University of Queensland Critical Thinking Project

Lesson 01 – Why Map?

We’ll take it as a given that thinking well is important. But what might not be so obvious however, is that thinking well, AKA critical thinking, is not something that comes naturally to humans.

All of us would like to think we are rational and deliberate creatures. Yet as psychologists have demonstrated time after time, humans have a tendency to engage in a wide range of irrational behaviours and faulty reasoning. 1

That’s why we need to learn to think critically. Don’t believe us? Then try this quick test ….

  1. A burger and fries cost $5.50 together. The burger costs $5 more than the fries. How much do the fries cost?

  2. The slime in an undergrad’s bathroom is growing fast, doubling in size every day. If it takes 48 days to completely cover the bathroom, how long does it take to cover half the bathroom?

  3. John plays rugby and like to go hunting and fishing with his dad. Which statement about him is most likely to be true:

a. John is a nurse.

b. John is a combat nurse in the Australian Army.

Show Answers

  1. The fries cost $0.25. $5.25 + $0.25 = $5.50.

  2. 47 days. If it doubles every day, then half the bathroom is covered the day before all the bathroom is covered.

  3. A) John is a nurse is more likely than John being a nurse AND in the army as B) is a subset of A).

If you didn’t get 100%, then don’t fret – your not alone. These questions are inspired by Shane Frederick’s Cognitive Reflection Test, which is designed to see how well people can overcome their natural cognitive biases. Few people get 3 out of 3.

Now most people don’t think about their own thinking. This is rather problematic because thinking about your thinking, AKA metacognition, is an essential part of becoming a critical thinker.

Luckily, there is a tool that can help.

Why Argument Maps?

Argument mapping is the visual depiction of inferential structure. Much like an x-ray does for our bodies, argument maps give us an insight into what’s going on inside our minds.

Argument mapping as a tool for improving our thinking has a pedigree that goes back over 100 years. Maps provide a useful focus point to, and scaffolding for, our reasoning processes.

A number of studies have shown that deliberate practce with argument mapping is an effective way of improving critical thinking skills. In one, a single course of argument mapping showed the same gains in reasoning skills as an entire undergraduate degree.

One of the main reasons that argument mapping has proven so useful as a thinking aid is that it accurately depicts our reasoning processes.

When we think to ourselves, we tend to think in associations.

Paris <==> France <==> Croissant <==> Yum!

Narrative is linear but our reasoning is not. When we think out loud or on paper, we are constrained by the linear structure of narrative. One sentence must come after another.

Argument maps don’t have that constraint. Argument maps are tree-like structures called directed graphs which more accurately represents good reasoning. Importantly, argument maps show the direction of our reasoning.

Consider the following argument …

You really shouldn’t smoke. Study after study has shown that smoking is a leading cause of lung cancer and other health problems and we only get one life. What’s more, the price of a pack of cigarettes is crazy high with all the taxes.

This argument seems rather straight forward (for non-smokers at least). Yet on closer inspection, there is quite a bit going on. How do the reasons provided support the conclusion? What is the conclusion? How does the price of cigarettes relate to their health impact?

Now let’s look at the same argument in map form.

It’s obvious now which claim is the conclusion. It’s also clear how the other claims support the main conclusion, and what important claims aren’t stated explicitly.

Argument maps are x-ray goggles for critical thinking! They can show us what’s going on in out own (and other’s) minds.

Click for Lesson 02


Frederick, S. (2005). Cognitive reflection and decision making. Journal of Economic Perspectives, 19, 25–42.

Twardy, C. (2004). Argument maps improve critical thinking. Teaching Philosophy, 27(2), 95–116. doi:10.5840/teachphil/200427213

Wigmore, J. H. (1913) The principles of judicial proof: As given by logic, psychology,and general experience, and illustrated in judicial trials (Vol. 1). Little, Brown, Retrieved from

  1. See Daniel Kahneman’s Thinking Fast and Slow for an easy introduction. 

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