Thinking, Fast and Slow

The preliminaries

• Simply put, we use two basic modes of thinking: System 1 and System 2.
  • System 1 operates automatically and quickly, with no sense of voluntary control (you smell fire and your instinct is to run).
  • System 2 is used for more complex mental activities (taking an exam) and it requires significant attention.
    • With System 2 operations, you’re doing something that doesn’t come naturally.
    • So, while it’s possible to do multiple System 2 operations at once, they have to be easy. You couldn’t compute the product of 142 x 345 while making a left turn into dense traffic during a thunderstorm, and you certainly shouldn’t try.
• The interaction between the two is fascinating.
  • For instance, a happy mood loosens System 2’s control over performance: you become more intuitive and creative but also less vigilant and more prone to logical errors.
  • A good mood is a signal that things are going well, the environment is safe, and it’s all right to let your guard down.

System 1 and System 2

• System 1 continuously generates suggestions for System 2: impressions, intuitions, intentions, and feelings. It works even when you’re sleeping.
  • If System 2 endorses those, then the impressions and intuitions turn into beliefs, and impulses turn into voluntary actions.
  • Studies of brain responses have shown that violations of normality are detected with astonishing speed and subtlety (via System 1). (Like when an upper-class voice says, “I have a large tattoo on my back.”)
• But when System 1 runs into difficulty, it calls on System 2 for more detailed processing.
  • That is, System 2 is activated when your brain detects an event that violates the model of the world that System 1 maintains–you can usually feel a surge of conscious attention.
    • You will stare, pause, think, etc., to make sense of the event.
  • System 2 also continuously monitors your behavior–it’s the control that keeps you polite when you’re angry, alert when you’re driving during a storm.
• In sum, most of what you think and do originates in System 1, but System 2 takes over when things get difficult.
  • The arrangement works well most of the time because System 1 is pretty good at what it does: its models of familiar situations are accurate, as are its short-term predictions, and its initial reactions to challenges are generally appropriate. 

Attention and effort

• System 2 operations are effortful and one of its main characteristics is laziness–it’s reluctant to invest more effort than is strictly necessary.
  • So, the thoughts and actions that System 2 believes it has chosen are often guided by System 1.
  • That said, there are things that only System 2 can perform because they require an effort to overcome System 1’s intuitions.
• For example:
  • Make up several strings of 4 digits, all different, and write each on an index card.
  • Place a blank card on top of the deck.
  • Then you’ll do Add-1:
    • Start beating a steady rhythm, one beat per second. Remove the blank card and read the four digits. Wait for two beats, then report a string in which each digit is incremented by 1. So 5294 becomes 6305. 
    • You can also try this with Add-3.
• Switching from one task to another is effortful, especially under time pressure.
  • We normally avoid mental overload by dividing our tasks into multiple easy steps, writing things on paper rather than overloading our memories.
  • As you become skilled in a task, its demand for energy diminishes.

The lazy controller

• System 2 has a natural speed.
  • For example, maybe you can think while strolling, but it’s hard to do Add-3 while strolling–work that imposes a heavy load on short-term memory.
    • If you have to do something incredibly complex under time pressure, you would rather likely be still, and prefer sitting to standing.
  • And if you walk faster than your strolling speed, this change results in a sharp decline in your ability to think coherently.
• This means that, for most of us, most of the time, maintaining a coherent train of thought and the occasional engagement in effortful thinking also requires self-control.
• Self-control and cognitive effort are forms of mental work.
  • People who are cognitively busy are also more likely to make selfish choices, use sexist language, and make superficial judgements.
    • Alcohol can have the same effect, as does a sleepless night.
    • Too much concern for how well one is doing in a task can disrupt performance by loading short-term memory with pointless anxious thoughts.
• So, activities that impose high demands on System 2 require self-control, and the exertion of self-control is depleting and unpleasant.
  • After exerting self-control here, you do not feel like making an effort there.
  • (Interestingly, in one experiment, researchers discovered that because the nervous system consumes more glucose than most other parts of the body, when you’re actively involved in difficult cognitive reasoning, your blood glucose level drops.)
• How closely does System 2 monitor System 1’s suggestions?
  • For example: A bat and a ball cost $1.10. The bat costs one dollar more than the ball. How much does the ball cost?
    • The intuitive answer is 10 cents (the correct answer is 5 cents).
    • Many people pick the intuitive answer because they’re overconfident, and put too much faith in their intuitions–cognitive effort is mildly unpleasant and they seek to avoid it.
  • This also tells us that intelligence is not only the ability to reason, but also the ability to find relevant material in memory and to deploy attention when needed. And high intelligence doesn’t make people immune to these biases–another ability is involved, and that’s rationality.
  • Cognitive strain can mobilize System 2, which is more likely to reject System 1’s intuitive answer.

How we make judgments

• System 1 continuously monitors what’s going on outside and inside the mind and generates assessments without specific intent.
• System 1 is designed to jump to conclusions from little evidence, and it’s not designed to know the size of its jumps
  • Because of the subjective confidence we have in our opinions, the amount of evidence and quality don’t count for much.

Acquiring skill

• Certain types of intuitions are acquired very quickly–for instance, we inherited a great facility to learn when to be afraid.
• On many occasions, you may feel uneasy in a particular place or when someone uses a particular turn of phrase without having a conscious memory of the triggering event.
• Emotional learning may be quick, but what we consider “expertise” usually takes a long time to develop.
  • The acquisition of expertise in things such as high-level chess, basketball, or firefighting is intricate and slow because expertise in a domain isn’t a single skill but a large collection of mini-skills.

Bad events

• The human brain contains a mechanism that prioritizes bad news.
  • By shaving a few hundredths of a second from the time needed to detect a predator, this circuit improves the odds of living long enough to reproduce.
  • System 1’s automatic operations reflect this evolutionary history.
  • No comparably rapid mechanism for recognizing good news has been detected.
• For example, a single cockroach will completely wreck the appeal of a bowl of cherries, but a cherry will do nothing at all for a bowl of cockroaches.
  • The negative trumps the positive in many ways.
  • Bad emotions, bad parents, and bad feedback have more impact than good ones, and bad information is processed more thoroughly than good.

How to improve our systems

• Specifically, what can be done about biases?
  • It will require a considerable investment of effort, as System 1 is not readily educable.
• The way to block System 1 errors is simple in principle: recognize the signs that you’re in a cognitive minefield, slow down, and ask for System 2 reinforcement. 
• Also, better constructive criticism goes a long way.
  • Decision-makers can make better choices when they trust their critics to be sophisticated and fair, and when they expect their decision to be judged by how it was made, not only by how it turned out.

• The marvels of priming (exposure to one thing may influence a response to something else, without conscious guidance or intention)
• Jumping to conclusions (doing so on the basis of limited evidence is so important to an understanding of intuitive thinking)
• The halo effect (sequences matters because the halo effect increases the weight of first impressions, sometimes to the point that subsequent information is mostly wasted)
• How people manage to make judgments of probability without knowing precisely what probability is
• The affect heuristic (for example, your political preference determines the arguments that you find compelling)
• Cause and chance (we’re pattern seekers–random processes produce many sequences that convince people that the process isn’t random after all–assuming causality could have had evolutionary advantages, and it’s part of the general vigilance that we’ve inherited from ancestors)
• The anchoring effect (how free are you? You are always aware of the “anchor” in your mind and even pay attention to it, but you don’t know how it guides and constraints your thinking, because you can’t imagine how you would have thought if the anchor had been different)
• Stereotyping (it’s a bad word in our culture, but in psychology it’s neutral–one of the basic characteristics of System 1 is that it represents categories as norms and prototypes–stereotypies are how we think of categories)
• The illusion of understanding (we can’t help dealing with the limited information we have as if it were all there is to know – unfortunately, we have an almost unlimited ability to ignore our ignorance)
• Formulas are better than intuition (Apgar scores – staff in delivery rooms now have a consistent standard for determining which babies were in trouble, instead of relying on intuition)
• Action and inaction (people expect to have stronger emotional reactions to an outcome that is produced by action than to the same outcome when it is produced by inaction)