My goodness, this book is dense. Don’t get me wrong, it’s well written and very accessible – you could take it as a holiday read and “read through” it – but there is 25 years of psychology research packed into a few hundred pages. We covered this book in our System Test book club, and found that even covering a chapter or two each session, we had plenty to talk about and discuss.
Roughly speaking, the fundamental theme of this book is that we as humans have two systems in our brains, which Kahneman helpfully labels “System 1” and “System 2”.
- System 1 is fast, reactive, emotional, and runs on assumptions and work that the brain finds “easy” – analogies, associations, stereotypes, anecdotal evidence. It’s great for letting us deal with day to day life without going nuts.
- System 2 is the slow careful, rational thinking that we think we are all the time. It’s great for coming to the logically correct answer, but it’s way too expensive and slow for us to use all the time.
As System 2 is really expensive to run vs System 1, a lot of the time we actually use System 1 with System 2 unthinkingly rubber-stamping the answer. An early uncomfortable conclusion to the research is that we’re not the rational beings we think we are. The rest of the book covers ways in which we actually think, and the various heuristics and biases that we engage in, and so on. Kahneman has spent his life picking these apart and uses this model to give good explanations to why these come about, and what we can (and can’t!) do to try to get to the actual logical answers both at work and in general life.
I thoroughly recommend this book to anyone interested in their development, whether a tester or otherwise (Kahneman also provides a good bibliography and references if you’re interested in digging further). And if you’re thinking of starting some kind of discussion group or book club, this is a good “hook” book to get started with.