I haven’t done a book summary in ages, so this is long overdue. For the most part, this is a selfish exercise, because doing so helps me sift through a book to summarise the key messages - and this act, helps me embed the messages in my own mind. That said, I received a lot of good feedback from the last one, so I hope you find this useful too!
I’ve been following Professor Daniel Kahneman for over a decade, and his work has always fascinated me… I was working on a summary of a more recent book of his entitled Noise, and then realised how relevant Thinking, Fast and Slow was, so I decided to post this review first. The good news is I therefore have another draft nearly done for the next review, so you won’t wait as long!
In this book, the Nobel Prize winner tackles topics which are both complex and integral to the human mind. As the wiki pages states, the book's main thesis is a differentiation between two modes of thought: “System 1” is fast, instinctive and emotional; “System 2” is slower, more deliberative, and more logical. The books gets you to consider how your mind habitually contradicts itself, distorts data and misleads you. It’s an honest, refreshing take, and Kahneman often illustrates conflicted thinking with examples from his own life. Granted, it can be a slow read at times, but as anyone who has read it will tell you: it is well worth the time.
The “Two Systems” of mental processing
When you have to make sense of something, you simply think about it. To understand how this process of thinking actually happens, consider a model where people apply two cognitive systems.
The first is “System 1” - this is the mental processing which reads emotions and handles automatic skills, such as riding a bicycle or driving a car. System 1 is what takes over our thinking when we comprehend simple statements (e.g., “complete the phrase ‘You never really own a . . .’ ”), instinctively turn to see where a noise is coming from, or grimace when we see grotesque images. System 1 is responsible for creating associated meanings (including stereotypes) rapidly and involuntarily.
“Although System 2 believes itself to be where the action is, the automatic System 1 is the hero of the book.”
The second is “System 2” - this is activated when we focus on specific details, such as doing a tax return or deciding whether 6 or 12 eggs in the supermarket is better value. System 2 applies effort consciously; this applies when we do complicated math problems, try new physical activities or search for a specific person in a crowd. System 2 thinking is slower, but we need it for methodical thinking processes such as formal logic.
“The main function of System 1 is to maintain and update a model of your personal world, which represents what is normal in it.”
At a glance, System 2 might seem like the more valuable system, and System 1 may appear to be rather mechanical and unimportant; the reality is more nuanced. When we think, our mental processes engage in a “division of labour” and constantly interact. We primarily operate with System 1 engaged, where rapid processing is extremely efficient and necessary. Just consider how much your eyes actually see when you look anywhere, and how impossible it would be to process every single input in significant detail. In fact, you may have found yourself reasoning about a task in System 2, but then got tired or distracted and found that you’ve shifted over to System 1 without even realising it. If you have ever found yourself confused by an optical illusion, you have experienced what happens when these two systems are in conflict.
Activation and interaction of these systems
Which system is activated, and in turn, how we think, will depend on how much effort we are able to put in. When we’re doing something easy such as walking from our home to a train station nearby, this is a route which is known, and we would be using using System 1; in such instances, we have a lot of cognitive capacity left for thinking.
If we then decide to run for a train (leaving from the same station) when we might be at risk of missing it, System 2 switches on to maintain this elevated effort. During this run, if we tried to solve a math problem, we’d likely stop running or slow down, because our brains struggle with the additional burden. Studies have shown that intense concentration lowers the body’s glucose levels. If your System 2 is ‘busy’ (such as while running for a train), you’re more likely to stereotype, give in to temptation or consider issues more superficially.1
“People who are ‘cognitively busy’ are...more likely to make selfish choices, use sexist language and make superficial judgments in social situations.”
System 1 is what pushes us to jump to conclusions, or easy answers, so if what appears to be a correct solution appears when we face a challenge, System 1 will default to that answer, even if we get additional information later on which disproves the initial conclusion. System 1 performs rapid “associative activation.” When we pair two words, or a word and an image, our minds will link them and weave a story from these scraps of information.
You may have heard of “priming?” System 1 is exactly what priming relies on. If you see the word “banana” followed by the word “vomit,” your mind creates an instantaneous connection that causes a physical reaction. Similarly, if you are primed and shown the word with food or references to eating, it is more likely you would complete the sequence S-O-?-P as “soup” rather than “soap.”
“A compelling narrative fosters an illusion of inevitability.”
We actually see persuasion tactics which appeal to our System 1 preferences more often than we realise. For simple, memorable information, you may notice a bold font in text, rhyming slogans in advertising and company names which roll off the tongue and are easy to say. Heck, even the story about Rolex rings true here: