Thinking, Fast and Slow: Part 1, Chapter 5 Summary & Analysis

Kahneman describes how, when we are conscious, multiple computations are happening in our brains: to monitor that things are going well, that there are no threats, and that our attention should not be redirected. We are constantly evaluating whether we are experiencing cognitive ease (a sign that things are going well) or cognitive strain (in which we have to mobilize System 2). This means that a sentence that is printed in a clear font or color, or has been repeated, is processed with ease.

Kahneman next writes about illusions of memory. He writes down a few names: David Stenbill, Monica Bigoutski, Shana Tirana. After a few days, if we are shown a long list of names that includes these three, we will be likely to identify them as celebrities rather than an unknown person. This happens because we know someone is a minor celebrity based on our ability to recall having seen the name before, and this creates an illusion of memory.

We often make judgments based on whether information is cognitively easy to retrieve. Kahneman describes how he retook a driving test after moving to a new state. Some answers knew because he had driven for many years, but for some questions, for which there seemed to be no good answer, he simply relied on cognitive ease.

Messages are easier to believe if they are clearer—even font contrast, letter size, and paper quality make a difference. Kahneman advises not to use complex language when simpler language suffices, and that adages with rhymes are more likely to be taken as truth. All of these factors aid in cognitive ease.

Kahneman proves how cognitive ease can distort our processing. In a study, participants are given three questions (including the bat-and-ball problem) in which the intuitive answers are wrong. Half of the students saw the puzzles in a normal font, and 90% of this group made at least one mistake. The other half saw the puzzles in a less legible font, and only 35% of them made a mistake. Cognitive strain mobilizes System 2 and is more likely to reject the intuitive answer.

In other examples, participants in an experiment were shown pictures of objects, and smiled and relaxed more when the images were easier to see. Easily pronounced words evoke favorable attitudes; companies with pronounceable names do better than those without. Familiarity also breeds affection: participants in a study run by Robert Zajonc were shown words in a foreign language that they did not understand. They associated the words that were shown more frequently with good meanings.

Zajonc argued that the “exposure effect” has a long evolutionary history: that organisms react cautiously to new stimuli because they could represent danger, whereas familiar things are thought of favorably once we have learned that they do not cause anything bad to happen.

Cognitive ease is something we sense long before we are conscious of it. If people are shown three words (like dive, light, and rocket), they are often able to recognize that they share a word that connects them, even if they cannot immediately think of that word (which is sky).

Putting participants in this experiment in a good mood doubles their accuracy of recognizing if the words are linked. When in a good mood, people become more intuitive and more creative but also less vigilant and more prone to errors. This also makes biological sense: a good mood is a signal that the environment is safe and that it is all right to let one’s guard down.

Returning to the experiment with the connected words, if participants are told that their emotions are being influenced by good music, they do not have the same accuracy in connecting the words because they do not associate their emotional response with their determination of coherent or incoherent words. This demonstrates that the brief emotional response that follows the presentation of words (pleasant if they are coherent, unpleasant otherwise) is actually the basis of the judgment of coherence.