Chapter 1 : Two Systems

To observe your mind in automatic mode, glance at the image below.

Figure 1

Your experience as you look at the woman’s face seamlessly combines what we normally call seeing and intuitive thinking. As surely and quickly as you saw that the young woman’s hair is dark, you knew she is angry.Furthermore, what you saw extended into the future.You sensed that this woman is about to say some very unkind words, probably in a loud and strident voice.

Now look at the following problem:

17 × 24

You knew immediately that this is a multiplication problem, and probably knew that you could solve it, with paper and pencil, if not without. You also had some vague intuitive knowledge of the range of possible results. A precise solution did not come to mind, and you felt that you could choose whether or not to engage in the computation. If you have not done so yet, you should attempt the multiplication problem now, completing at least part of it.You experienced slow thinking as you proceeded through a sequence of steps.The process was mental work: deliberate, effortful, and orderly—a prototype of slow thinking.The computation was not only an event in your mind; your body was also involved. Your muscles tensed up, your blood pressure rose, and your heart rate increased.

We will refer to two systems in the mind, System 1 and System 2.

System 1 operates automatically and quickly, with little or no effort and no sense of voluntary control.

System 2 allocates attention to the effortful mental activities that demand it, including complex

computations. The operations of System 2 are often associated with the subjective experience of

agency, choice, and concentration.

The automatic operations of System 1 generate surprisingly complex patterns of ideas, but only the slower System 2 can construct thoughts in an orderly series of steps.

In rough order of complexity, here are some examples of the automatic activities that are attributed to System 1:

1) Detect that one object is more distant than

another.

2) Orient to the source of a sudden sound.

3) Complete the phrase “bread and…”

4) Make a “disgust face” when shown a horrible picture.

5) Detect hostility in a voice.

6) Answer to 2 + 2 = ?

7) Read words on large billboards.

8) Drive a car on an empty road.

9) Find a strong move in chess (if you are a chess master).

10) Understand simple sentences.

11) Recognize that a “meek and tidy soul with a passion for detail” resembles an occupational stereotype.

The highly diverse operations of System 2 have one feature in common: they require attention and are

disrupted when attention is drawn away. Here are some examples:

1) Brace for the starter gun in a race.

2) Focus attention on the clowns in the circus.

3) Focus on the voice of a particular person in a crowded and noisy room.

4) Look for a woman with white hair.

5) Search memory to identify a surprising sound.

6) Maintain a faster walking speed than is natural for you.

7) Monitor the appropriateness of your behavior in a social situation.

8) Count the occurrences of the letter a in a page of text.

9) Tell someone your phone number.

10) Park in a narrow space (for most people except garage attendants).

11) Compare two washing machines for overall value.

12) Fill out a tax form.

13) Check the validity of a complex logical argument.

In all these situations you must pay attention, and you will perform less well, or not at all, if you are not ready or if your attention is directed inappropriately.

System 2 has some ability to change the way System 1 works, by programming the normally automatic functions of attention and memory. When waiting for a relative at a busy train station, for example, you can set yourself at will to look for a white-haired woman or a bearded man, will to look for a white-haired woman or a bearded man, and thereby increase the likelihood of detecting your relative from a distance.

Intense focusing on a task can make people effectively blind, even to stimuli that normally attract attention. The most dramatic demonstration was offered by Christopher Chabris and Daniel Simons in their book The Invisible Gorilla. They constructed a short film of two teams passing basketballs, one team wearing white shirts, the other wearing black. The viewers of the film are instructed to count the number of passes made by the white team, ignoring the black players. This task is difficult and completely absorbing. Halfway through the video, a woman wearing a gorilla suit appears, crosses the court, thumps her chest, and moves on. The gorilla is in view for 9 seconds. Many thousands of people have seen the video, and about half of them do not notice anything unusual. It is the counting task—and especially the instruction to ignore one of the teams—that causes the blindness. No one who watches the video without that task would miss the gorilla. Seeing and orienting are automatic functions of System 1, but they depend on the allocation of some attention to the relevant stimulus. The authors note that the most remarkable observation of their study is that people find its results very surprising. Indeed, the viewers who fail to see the gorilla are initially sure that it was not there—they cannot imagine missing such a striking event. The gorilla study illustrates two important facts about our minds: we can be blind to the obvious, and we are also blind to our blindness.

Systems 1 and 2 are both active whenever we are awake. System 1 runs automatically and System 2 is normally in a comfortable low-effort and System 2 is normally in a comfortable low-effort mode, in which only a fraction of its capacity is engaged.System 1 continuously generates suggestions for System 2: impressions, intuitions, intentions, and feelings. If endorsed by System 2, impressions and intuitions turn into beliefs, and impulses turn into voluntary actions.When all goes smoothly, which is most of the time, System 2 adopts the suggestions of System 1 with little or no modification.When System 1 runs into difficulty, it calls on System 2 to support more detailed and specific processing that may solve the problem of the moment.

System 1 is generally very good at what it does: its models of familiar situations are accurate, its short-term predictions are usually accurate as well, and its initial reactions to challenges are swift and generally appropriate. System 1 has biases, however, systematic errors that it is prone to make in specified circumstances.One further limitation of System 1 is that it cannot be turned off. If you are shown a word on the screen in a language you know, you will read it— unless your attention is totally focused elsewhere.