The main function of System 1, Kahneman reiterates, is to maintain and update the model of the world, which represents what is normal within it. On a second occasion of an abnormality, people become distinctly less surprised. Kahneman provides an example: he and his wife were driving from New York City to Princeton and saw a car on fire by the side of the road. When this happened again at the same part of the road some weeks later, they were less surprised, and even had a future expectation of seeing a burning car when they passed the same stretch after that. The second abnormality will retrieve the first from memory, and both make sense together.
This kind of processing of surprise serves as a way of illustrating how we construct stories in order to make sense of the world. We become less surprised as we start to construct a story about surprising events that share a pattern, as Kahneman and his wife discover in these two incidents with the burning cars. They construct a story about this stretch of the road and come to connect it with accidents.
“How many animals of each kind did Moses take into the ark?” Kahneman asks. Very few people detect what is wrong with the question, because the animals in the ark set up a biblical context, and Moses makes sense in that context.
Like the bias inherent in cognitive ease, when an idea is not surprising in a given context we devote less attention to it and are less likely to detect abnormalities about it.
Violations of normality, however, are detected with a great degree of speed and subtlety. A problem will immediately emerge from the sentence “Earth revolves around the trouble each year,” or a male voice saying, “I believe I am pregnant,” or an upper-class voice saying, “I have a large tattoo on my back.” These statements violate the norms and patterns that System 1 has constructed over time.
Even though System 1 has its flaws in terms of ruling things normal or abnormal, there are some areas in which it is not easily fooled: concepts that defy grammar, logic, universal rules of biology, even simply common social patterns. When those patterns are broken, System 2 is then mobilized.
Kahneman writes, “Fred’s parents arrived late. The caterers were expected soon. Fred was angry.” He points out that we know why Fred was angry, and it was not because the caterers were expected soon. Anger and lack of punctuality are linked as effect and possible cause. We see causality in everything, including in videos of triangles in which one appears to bully another. Kahneman explains that using causality to explain situations that require statistical reasoning is a recurrent theme in the book.
The patterns that System 1 constructs over our lifetime allow us to predict events, relating one thing to another. In this example, Fred’s parents arriving late causes Fred to be angry; that is how we are able to make sense of these sentences together. We encounter issues, however, when we mistakenly attribute causality to random occurrences.