Book Cover

Chapter 2 tackles the relationship between effort, attention, and thinking slow. Thinking slow, system 2 thinking, requires effort. That effort must be marshaled and directed which requires attention. The more effort needed, the more attention needed. Attention is a finite resource, therefore, the more we spend on system 2 thinking, less attention available for everything else. A word of warning, don’t do higher math while driving!

Kahneman uses an exercise to illustrate that system 2 thinking taxes the brain by requiring significant mental effort. The exercise requires the participant to add one to each numeral in a four-digit number (1234 would be 2345). A tougher version adds 3 to each digit. The level of effort can be seen by the amount of pupil constriction by the person performing the exercise. The harder the exercise the more thought is needed. The more thought, the smaller the pupils. In essence, the brain is allocating more and more attention to the thinking process. This explains why when you are working on a difficult problem it is easy to ignore everything going on around you.

There are other scenarios that impact the amount of effort and attention needed to perform slow thinking. As a person gains skill in a task that requires system 2 thinking, the amount of effort to generate answer goes down. The thinking process becomes more automatic, more system 1 in nature. Answering email can never become a system 1 thinking process, each email is a continual learning process that requires conscious thought and decision making.

Another twist in the effort and attention relationship for system 2 thinking is the amount of effort needed to maintain several ideas in memory simultaneously. Keeping multiple items in your head increases the amount of effort and attention needed. This is why trying to remember a shopping list in your head while driving is a fool’s errand. How many times have you eschewed a list only to get home to find that you’ve forgotten one or more items. This problem is why advise developers that think they will remember everything they discovered while planning to buy a notebook and take notes. A further complication that impacts the effort and attention needed for slow thinking is time pressure. Time pressure further increases the effort and attention substantially for system 2 thinking. Time pressure is the arch nemesis of good coding and testing.

The relationship between the amount of effort and the amount of attention needed to perform slow thinking is an important consideration when developing a process or workflow. Creating an environment in which a person can focus attention will increase their effectiveness.

If you do not have a favorite, dog-eared copy of Thinking, Fast and Slow, please buy a copy. Using the links in this blog entry helps support the blog and its alter-ego, The Software Process and Measurement Cast. Buy a copy on Amazon, It’s time to get reading!

Previous installments:
Week 1: Logistics and Introduction
Week 2: The Characters Of The Story