Heuristic Quotes

The psychologist Gerd Gigerenzer has a simple heuristic. Never ask the doctor what you should do. Ask him what he would do if he were in your place. You would be surprised at the difference

This is the essence of intuitive heuristics: when faced with a difficult question, we often answer an easier one instead, usually without noticing the substitution.

Outlier complacency' is a heuristic that allows a person to enjoy the thrill of danger associated with the possible negative outcome of an activity or event because they take comfort in the reality that the likelihood of an actual negative outcome is statistically low.

Nothing in life is as important as you think it is when you are thinking about it.

Clean code is not written by following a set of rules. You don’t become a software craftsman by learning a list of heuristics. Professionalism and craftsmanship come from values that drive disciplines.

I propose that if you want a simple step to a higher form of life, as distant from the animal as you can get, then you may have to denarrate, that is, shut down the television set, minimize time spent reading newspapers, ignore the blogs. Train your reasoning abilities to control your decisions; nudge System 1 (the heuristic or experiential system) out of the important ones. Train yourself to spot the difference between the sensational and the empirical. This insulation from the toxicity of the world will have an additional benefit: it will improve your well-being.

By now they had mastered my own language, but they still made simple mistakes, like using 'hermeneutics,' when they meant 'heuristic'.

Life is full of signs. The trick is to know how to read them. Ghosh called this heuristics, a method for solving a problem for which no formula exists.

If you want to create the common sense that comes from twenty years of being in the world, you need to devote twenty years to the task. You can't assemble an equivalent collection of heuristics in less time; experience is algorithmically incompressible.

You will soon realize you are not so smart, and thanks to a plethora of cognitive biases, faulty heuristics, and common fallacies of thought, you are probably deluding yourself minute by minute just to cope with reality.

A heuristic we follow is that whenever we feel the need to comment something, we write a method instead.

There are two parts to learning craftsmanship: knowledge and work. You must gain the knowledge of principles, patterns, practices, and heuristics that a craftsman knows, and you must also grind that knowledge into your fingers, eyes, and gut by working hard and practicing.

Chance is commonly viewed as a self-correcting process in which a deviation in one direction induces a deviation in the opposite direction to restore the equilibrium. In fact, deviations are not "corrected" as a chance process unfolds, they are merely diluted.

If someone you know gets sick from taking a flu shot, you will be less likely to get one even if it is statistically safe. In fact, if you see a story on the news about someone dying from the flu shot, that one isolated case could me enough to keep you away from the vaccine forever. On the other hand, if you hear a news story about how eating sausage leads to anal cancer, you will be skeptical, because it has never happened to anyone you know, and sausage, after all, is delicious. The tendency to react more rapidly and to a greater degree when considering information you are familiar with is called the availability heuristic.

An ignorant mind is precisely not a spotless, empty vessel, but one that’s filled with the clutter of irrelevant or misleading life experiences, theories, facts, intuitions, strategies, algorithms, heuristics, metaphors, and hunches that regrettably have the look and feel of useful and accurate knowledge.

The psychologist Gerd Gigerenzer has a simple heuristic. Never ask the doctor what you should do. Ask him what he would do if he were in your place. You would be surprised at the difference.

To understand the future, you do not need technoautistic jargon, obsession with “killer apps,” these sort of things. You just need the following: some respect for the past, some curiosity about the historical record, a hunger for the wisdom of the elders, and a grasp of the notion of “heuristics,” these often unwritten rules of thumb that are so determining of survival. In other words, you will be forced to give weight to things that have been around, things that have survived.

For example, students of policy have noted that the availability heuristic helps explain why some issues are highly salient in the public’s mind while others are neglected. People tend to assess the relative importance of issues by the ease with which they are retrieved from memory—and this is largely determined by the extent of coverage in the media

Heuristic is an algorithm in a clown suit. It’s less predictable, it’s more fun, and it comes without a 30-day, money-back guarantee.

Something, somewhere, somewhen, must have happened differently... PETUNIA EVANS married Michael Verres, a Professor of Biochemistry at Oxford. HARRY JAMES POTTER-EVANS-VERRES grew up in a house filled to the brim with books. He once bit a math teacher who didn't know what a logarithm was. He's read Godel, Escher, Bach and Judgment Under Uncertainty: Heuristics and Biases and volume one of The Feynman Lectures on Physics. And despite what everyone who's met him seems to fear, he doesn't want to become the next Dark Lord. He was raised better than that. He wants to discover the laws of magic and become a god. HERMIONE GRANGER is doing better than him in every class except broomstick riding. DRACO MALFOY is exactly what you would expect an eleven-year-old boy to be like if Darth Vader were his doting father. PROFESSOR QUIRRELL is living his lifelong dream of teaching Defense Against the Dark Arts, or as he prefers to call his class, Battle Magic. His students are all wondering what's going to go wrong with the Defense Professor this time. DUMBLEDORE is either insane, or playing some vastly deeper game which involved setting fire to a chicken. DEPUTY HEADMISTRESS MINERVA MCGONAGALL needs to go off somewhere private and scream for a while. Presenting: HARRY POTTER AND THE METHODS OF RATIONALITY You ain't guessin' where this one's going.

She wants to tell them that Blue Gamma was more right than it knew: experience isn’t merely the best teacher; it’s the only teacher. If she’s learned anything raising Jax, it’s that there are no shortcuts; if you want to create the common sense that comes from twenty years of being in the world, you need to devote twenty years to the task. You can’t assemble an equivalent collection of heuristics in less time; experience is algorithmically incompressible.

If the rule of thumb for attention literacy is to pay attention to your intention, then the heuristic for crap detection is to make skepticism your default.

You can tell if a discipline is BS if the degree depends severely on the prestige of the school granting it. I remember when I applied to MBA programs being told that anything outside the top ten or twenty would be a waste of time. On the other hand a degree in mathematics is much less dependent on the school (conditional on being above a certain level, so the heuristic would apply to the difference between top ten and top two thousand schools). The same applies to research papers. In math and physics, a result posted on the repository site arXiv (with a minimum hurdle) is fine. In low-quality fields like academic finance (where papers are usually some form of complicated storytelling), the “prestige” of the journal is the sole criterion.

A BS DETECTION HEURISTIC The heuristic here would be to use education in reverse: hire, conditional on an equal set of skills, the person with the least label-oriented education. It means that the person had to succeed in spite of the credentialization of his competitors and overcome more serious hurdles. In addition, people who didn’t go to Harvard are easier to deal with in real life.

Heuristics are simplified rules of thumb that make things simple and easy to implement. But their main advantage is that the user knows that they are not perfect, just expedient, and is therefore less fooled by their powers. They become dangerous when we forget that.

People are often unaware of their own unawareness

One of the causes of status quo bias is a lack of attention. Many people adopt what we will call the “yeah, whatever” heuristic.

Markowitz’s strategy can be viewed as one example of what might be called the diversification heuristic. “When in doubt, diversify.

thanks to a plethora of cognitive biases, faulty heuristics, and common fallacies of thought, you are probably deluding yourself minute by minute just to cope with reality.

The technical definition of heuristic is a simple procedure that helps find adequate, though often imperfect, answers to difficult questions. The

Fast thinking includes both variants of intuitive thought—the expert and the heuristic

the availability heuristic: the easier it is to recall examples of an event, the more probable people think it is.

Soul-making is a journey that takes time, effort, skill, knowledge, intuition, and courage. It is helpful to know that all work with soul is process—alchemy, pilgrimage, and adventure—so that we don’t expert instant success or even any kind of finality. All goals and all endings are heuristic, important in their being imagined, but never literally fulfilled. In

The technical definition of heuristic is a simple procedure that helps find adequate, though often imperfect, answers to difficult questions. The word comes from the same root as eureka.

If the heuristic and analytic power of science can be joined with the introspective creativity of the humanities, human existence will rise to an infinitely more productive and interesting meaning.

I will scatter a few nuts on the frosting,’ said Maxwell, and he pushed the lever for that. This sifted handfuls of words like chthonic and heuristic and prozymeides through the thing so that nobody could doubt it was a work of philosophy.

The dominance of conclusions over arguments is most pronounced where emotions are involved. The psychologist Paul Slovic has proposed an affect heuristic in which people let their likes and dislikes determine their beliefs about the world.

The psychologist Paul Slovic has proposed an affect heuristic in which people let their likes and dislikes determine their beliefs about the world. Your political preference determines the arguments that you find compelling. If you like the current health policy, you believe its benefits are substantial and its costs more manageable than the costs of alternatives.

When you make an absolute statement, you assume a sense of personal integrity based on a pretense of moral objectivity, which exists only as a faulty heuristic to arrive at an easy conclusion, and deny yourself the responsibility of choice - it's more convenient not to acknowledge your freedom and settle for a less desirable outcome on the grounds that you had no choice, rather than risk acquiring the less desirable outcome by your own will, regardless of the possibility for a better one.

The peripheral route of influence refers to factors that are outside of the message itself, but still have considerable sway on how we make decisions. It includes essential elements of selling such as building rapport, compellingly presenting a product or service, and enhancing trust. This method of influence is made up of a series of mental reflexes, known as “heuristics.

These moments—when we are caught in a situation that has no clear answer, no heuristic to employ that will spit out a theoretical but practically impossible “correct” decision—are when we see the true value in failure. We’re deciding to do something that will, someday, backfire. The more we chew on it and work it through, the more meaning we can derive from that backfire when it happens.

We used the word “heuristics” to describe aspects of software development that tip toward the liberal arts. Its counterpart, “algorithms,” was its alter ego on the technical side. Heuristics and algorithms are like two sides of the same coin. Both are specific procedures for making software do what it does: taking input, applying an operation, and producing output. Yet each had a different purpose.

In short, critical theorists develop ways to “criticize” perceived structures and systems of oppression in order to bring about radical change. It offers a heuristic for understanding all human interaction through power dynamics between groups. When applied to race, concepts like white privilege, whiteness, and intersectionality purport to explain why there are disparities in outcomes among racial groups.

When the question is difficult and a skilled solution is not available, intuition still has a shot: an answer may come to mind quickly—but it is not an answer to the original question. The question that the executive faced (should I invest in Ford stock?) was difficult, but the answer to an easier and related question (do I like Ford cars?) came readily to his mind and determined his choice. This is the essence of intuitive heuristics: when faced with a difficult question, we often answer an easier one instead, usually without noticing the substitution.

Although it might be heuristically useful to bear in mind what one has actually observed, in principle, he argued, 'it is quite wrong to try founding a theory on observable magnitudes alone'. 'In reality the very opposite happens. It is the theory which decides what we can observe.

The uncomfortable, as well as the miraculous, fact about the human mind is how it varies from individual to individual. The process of treatment can therefore be long and complicated. Finding the right balance of drugs, whether lithium salts, anti-psychotics, SSRIs or other kinds of treatment can be a very hit or miss heuristic process requiring great patience and classy, caring doctoring. Some patients would rather reject the chemical path and look for ways of using diet, exercise and talk-therapy. For some the condition is so bad that ECT is indicated. One of my best friends regularly goes to a clinic for doses of electroconvulsive therapy, a treatment looked on by many as a kind of horrific torture that isn’t even understood by those who administer it. This friend of mine is just about one of the most intelligent people I have ever met and she says, “I know. It ought to be wrong. But it works. It makes me feel better. I sometimes forget my own name, but it makes me happier. It’s the only thing that works.” For her. Lord knows, I’m not a doctor, and I don’t understand the brain or the mind anything like enough to presume to judge or know better than any other semi-informed individual, but if it works for her…. well then, it works for her. Which is not to say that it will work for you, for me or for others.

The nature of news is likely to distort people’s view of the world because of a mental bug that the psychologists Amos Tversky and Daniel Kahneman called the Availability heuristic: people estimate the probability of an event or the frequency of a kind of thing by the ease with which instances come to mind.11

students of policy have noted that the availability heuristic helps explain why some issues are highly salient in the public’s mind while others are neglected. People tend to assess the relative importance of issues by the ease with which they are retrieved from memory—and this is largely determined by the extent of coverage in the media.

The scientist’s behavior while facing the refutation of his ideas has been studied in depth as part of the so-called attribution bias. You attribute your successes to skills, but your failures to randomness. This explains why these scientists attributed their failures to the “ten sigma” rare event, indicative of the thought that they were right but that luck played against them. Why? It is a human heuristic that makes us actually believe so in order not to kill our self-esteem and keep us going against adversity.

The problem is that we humans are prone to the availability heuristic, by which the salient is mistaken for the statistical, and the conspicuous and emotional effect of an event makes us think it is occurring more regularly than in reality. This helps us to be prudent and careful in daily life, forcing us to add an extra layer of protection, but

For example, students of policy have noted that the availability heuristic helps explain why some issues are highly salient in the public’s mind while others are neglected. People tend to assess the relative importance of issues by the ease with which they are retrieved from memory—and this is largely determined by the extent of coverage in the media.

Searching for wisdom in historic events requires an act of faith—a belief in the existence of recurrent patterns waiting to be discovered.

We learn from history that man can never learn anything from history.

The Affect Heuristic The dominance of conclusions over arguments is most pronounced where emotions are involved.

the essence of intuitive heuristics: when faced with a difficult question, we often answer an easier one instead, usually without noticing the substitution.

The reliance on the heuristic caused predictable biases (systematic errors) in their predictions.

When it comes to buying lottery tickets, fearing the West Nile virus, looking for child molesters, and so on, you use the availability heuristic first and the facts second.

The tendency to make poor decisions and ignore odds in favor of your gut feelings is called the affect heuristic.

The principle of adaptationism has been adopted so widely by Darwinians because it is such a heuristic methodology.

Hal (for Heuristically programmed ALgorithmic computer, no less) was a masterwork of the third computer breakthrough.

The consulting firm McKinsey & Co. estimates that in the United States, only 30 percent of job growth now comes from algorithmic work, while 70 percent comes from heuristic work.9

We called this reliance on the ease of memory search the availability heuristic.

The technical definition of heuristic is a simple procedure that helps find adequate, though often imperfect, answers to difficult questions.

The psychologist Paul Slovic has proposed an affect heuristic in which people let their likes and dislikes determine their beliefs about the world.

The question that the executive faced (should I invest in Ford stock?) was difficult, but the answer to an easier and related question (do I like Ford cars?) came readily to his mind and determined his choice. This is the essence of intuitive heuristics: when faced with a difficult question, we often answer an easier one instead, usually without noticing the substitution.

Ratio became a working hypothesis, a heuristic principle, and thus led to the incomparable rise of technology. This was something fundamentally new in world history. From the Egyptian pyramids to the Greek temples, from the medieval cathedrals up to the eighteenth century, technology was a matter of handicraft. It served religion, royalty, culture, and people’s daily needs.

Website aesthetics are crucial for a number of reasons. First, people use aesthetics as a heuristic for quality; if your website is aesthetically pleasing, they’ll assume your content is above average, and vice versa. This benefit leads to a second benefit: aesthetics will influence website visitors to actually evaluate your content, a decision that’s usually made within 50 milliseconds

special case of this rule of thumb is what might be called the “1/n” heuristic: “When faced with ‘n’ options, divide assets evenly across the options.”3 Put the same number of eggs in each basket.

the psychologist Jonathan Haidt said in another context, “The emotional tail wags the rational dog.” The affect heuristic simplifies our lives by creating a world that is much tidier than reality.

I discovered that I had been intuitively using the less-is-more idea as an aid in decision making (contrary to the method of putting a series of pros and cons side by side on a computer screen). For instance, if you have more than one reason to do something (choose a doctor or veterinarian, hire a gardener or an employee, marry a person, go on a trip), just don’t do it. It does not mean that one reason is better than two, just that by invoking more than one reason you are trying to convince yourself to do something. Obvious decisions (robust to error) require no more than a single reason. Likewise the French army had a heuristic to reject excuses for absenteeism for more than one reason, like death of grandmother, cold virus, and being bitten by a boar. If someone attacks a book or idea using more than one argument, you know it is not real: nobody says “he is a criminal, he killed many people, and he also has bad table manners and bad breath and is a very poor driver.

The art of reasoned persuasion is an iterative, recursive heuristic, meaning that we must go back and forth between the facts and the rules until we have a good fit. We cannot see the facts properly until we know what framework to place them into, and we cannot determine what framework to place them into until we see the basic contours of the facts. The great economist Friedrich Hayek said, “Without a theory, the facts are silent.

Heuristics also have a measurement or value associated with them—the duration for an animation or the red-green-blue values for an onscreen color, but there isn’t a similar “arrow of improvement” that always points the same way. Unlike evaluating algorithms, heuristics are harder to nail down. For instance, how quickly should a scrolling list glide to a stop after you’ve flicked it? We always made demos to evaluate the possibilities.

We proposed that they used resemblance as a simplifying heuristic (roughly, a rule of thumb) to make a difficult judgment. The reliance on the heuristic caused predictable biases (systematic errors) in their predictions.

it’s crucial to make the right call about whether to use an algorithm or a heuristic in a specific situation. This is why the Google experiment with forty-one shades of blue seems so foreign to me, accustomed as I am to the Apple approach. Google used an A/B test to make a color choice. It used a single predetermined value criterion and defined it like so: The best shade of blue is the one that people clicked most often in the test. This is an algorithm.

The first heuristic addresses the asymmetry in rewards and punishment, or transfer of fragility between individuals. Ralph Nader has a simple rule: people voting for war need to have at least one descendant (child or grandchild) exposed to combat. For the Romans, engineers needed to spend some time under the bridge they built—something that should be required of financial engineers today. The English went further and had the families of the engineers spend time with them under the bridge after it was built.

Substituting one question for another can be a good strategy for solving difficult problems, and George Pólya included substitution in his classic How to Solve It: “If you can’t solve a problem, then there is an easier problem you can solve: find it.” Pólya’s heuristics are strategic procedures that are deliberately implemented by System 2. But the heuristics that I discuss in this chapter are not chosen; they are a consequence of the mental shotgun, the imprecise control we have over targeting our responses to questions.

Heuristics are simplified rules of thumb that make things simple and easy to implement. But their main advantage is that the user knows that they are not perfect, just expedient, and is therefore less fooled by their powers. They become dangerous when we forget that.

people rely on a limited number of heuristic principles which reduce the complex tasks of assessing probabilities and predicting values to simpler judgmental operations. In general, these heuristics are quite useful, but sometimes they lead to severe and systematic errors.

The answer was straightforward: instances of the class will be retrieved from memory, and if retrieval is easy and fluent, the category will be judged to be large. We defined the availability heuristic as the process of judging frequency by “the ease with which instances come to mind.

Insight, then. Wisdom. The quest for knowledge, the derivation of theorems, science and technology and all those exclusively human pursuits that must surely rest on a conscious foundation. Maybe that's what sentience would be for— if scientific breakthroughs didn't spring fully-formed from the subconscious mind, manifest themselves in dreams, as full-blown insights after a deep night's sleep. It's the most basic rule of the stymied researcher: stop thinking about the problem. Do something else. It will come to you if you just stop being conscious of it... Don't even try to talk about the learning curve. Don't bother citing the months of deliberate practice that precede the unconscious performance, or the years of study and experiment leading up to the gift-wrapped Eureka moment. So what if your lessons are all learned consciously? Do you think that proves there's no other way? Heuristic software's been learning from experience for over a hundred years. Machines master chess, cars learn to drive themselves, statistical programs face problems and design the experiments to solve them and you think that the only path to learning leads through sentience? You're Stone-age nomads, eking out some marginal existence on the veldt—denying even the possibility of agriculture, because hunting and gathering was good enough for your parents. Do you want to know what consciousness is for? Do you want to know the only real purpose it serves? Training wheels. You can't see both aspects of the Necker Cube at once, so it lets you focus on one and dismiss the other. That's a pretty half-assed way to parse reality. You're always better off looking at more than one side of anything. Go on, try. Defocus. It's the next logical step.

Most people give substantial weight to anecdotal evidence, perhaps so much that it will cancel out positive recommendations found in consumer reports. People's tendency to give undue weight to some types of information is called the availability heuristic. A heuristic is a rule of thumb, a mental shortcut. Suppose someone asked you a question like what's more common in English, words that start with the letter to r words that have t as the third letter. You would have an easier time generating words that started with the letter t. Words starting with t would be more 'available'.

The availability heuristic, like other heuristics of judgment, substitutes one question for another: you wish to estimate the size of a category or the frequency of an event, but you report an impression of the ease with which instances come to mind. Substitution of questions inevitably produces systematic errors.

Part 2 updates the study of judgment heuristics and explores a major puzzle: Why is it so difficult for us to think statistically? We easily think associatively, we think metaphorically, we think causally, but statistics requires thinking about many things at once, which is something that System 1 is not designed to do.

As noted earlier, behavioral economists and evolutionary psychologists have demonstrated that most human decisions are based on emotional reactions and heuristic shortcuts rather than on rational analysis, and that while our emotions and heuristics were perhaps suitable for dealing with life in the Stone Age, they are woefully inadequate in the Silicon Age.

Amos liked the idea of an adjust-and-anchor heuristic as a strategy for estimating uncertain quantities: start from an anchoring number, assess whether it is too high or too low, and gradually adjust your estimate by mentally “moving” from the anchor. The adjustment typically ends prematurely, because people stop when they are no longer certain that they should move farther.

On another occasion, Amos and I wondered about the rate of divorce among professors in our university. We noticed that the question triggered a search of memory for divorced professors we knew or knew about, and that we judged the size of categories by the ease with which instances came to mind. We called this reliance on the ease of memory search the availability heuristic.

We tend to resolve our perplexity arising out of the experience that other people see the world differently than we see it ourselves by declaring that these others, in consequence of some basic intellectual and moral defect, are unable to see things “as they really are” and to react to them “in a normal way.” We thus imply, of course, that things are in fact as we see them, and that our ways are the normal ways. (Ichheiser, 1949, p. 39)

We should finally note a more radical challenge to the concept of Platonic utility that arises from nascent work in the reinforcement learning field under the rubric of intrinsic motivation. One idea is that the "true" evolutionarily appropriate metric for behavior is the extremely sparse one of propagating ones genes. What we think of as a Platonic utility over immediate rewards such as food or water, would merely be a surrogate that helps overcome the otherwise insurmountable credit assignment path associated with procreation. In these terms, even the Platonic utility is the same sort of heuristic expedient as the Pavlovian controller itself, with evolutionary optimality molding approximate economic rationality to its own ends. It as a sober thought that understanding values may be less important as a way of unearthing the foundations of choice that we might have expected.

argues the evolutionary psychologist Gerd Gigerenzer: we have survived and thrived not despite our cognitive biases but because of them. These so-called biases are the underpinnings of our heuristics, the unconscious mental shortcuts we take every time we use a ‘rule of thumb’ to make decisions. Over millennia, the human brain has evolved to rely on quick decision-making tools in a fast-moving and uncertain world, and in many contexts those heuristics lead us to make better decisions than exact calculations would do.

The conclusion is that the ease with which instances come to mind is a System 1 heuristic, which is replaced by a focus on content when System 2 is more engaged. Multiple lines of evidence converge on the conclusion that people who let themselves be guided by System 1 are more strongly susceptible to availability biases than others who are in a state of higher vigilance. The following are some conditions in which people “go with the flow” and are affected more strongly by ease of retrieval than by the content they retrieved:

The Endowed Progress Effect Punch cards are often used by retailers to encourage repeat business. With each purchase, customers get closer to receiving a free product or service. These cards are typically awarded empty and in effect, customers start at zero percent complete. What would happen if retailers handed customers punch cards with punches already given? Would people be more likely to take action if they had already made some progress? An experiment sought to answer this very question.[lxvi] Two groups of customers were given punch cards awarding a free car wash once the cards were fully punched. One group was given a blank punch card with 8 squares and the other given a punch card with 10 squares but with two free punches. Both groups still had to purchase 8 car washes to receive a free wash; however, the second group of customers — those that were given two free punches — had a staggering 82 percent higher completion rate. The study demonstrates the endowed progress effect, a phenomenon that increases motivation as people believe they are nearing a goal. Sites such as LinkedIn and Facebook utilize this heuristic to encourage people to divulge more information about themselves when completing their online profiles. On LinkedIn, every user starts with some semblance of progress (figure 19). The next step is to “Improve Your Profile Strength” by supplying additional information.

Finance is concerned with the relations between the values of securities and their risk, and with the behavior of those values. It aspires to be a practical, like physics or chemistry or electrical engineering. As John Maynard Keynes once remarked about economics, “If economists could manage to get themselves thought of as humble, competent people on a level with dentists, that would be splendid.” Dentists rely on science, engineering, empirical knowledge, and heuristics, and there are no theorems in dentistry. Similarly, one would hope that nance would be concerned with laws rather than theorems, with behavior rather than assumptions. One doesn’t seriously describe the behavior of a market with theorems.

CHARACTERISTICS OF SYSTEM 1 generates impressions, feelings, and inclinations; when endorsed by System 2 these become beliefs, attitudes, and intentions operates automatically and quickly, with little or no effort, and no sense of voluntary control can be programmed by System 2 to mobilize attention when a particular pattern is detected (search) executes skilled responses and generates skilled intuitions, after adequate training creates a coherent pattern of activated ideas in associative memory links a sense of cognitive ease to illusions of truth, pleasant feelings, and reduced vigilance distinguishes the surprising from the normal infers and invents causes and intentions neglects ambiguity and suppresses doubt is biased to believe and confirm exaggerates emotional consistency (halo effect) focuses on existing evidence and ignores absent evidence (WYSIATI) generates a limited set of basic assessments represents sets by norms and prototypes, does not integrate matches intensities across scales (e.g., size to loudness) computes more than intended (mental shotgun) sometimes substitutes an easier question for a difficult one (heuristics) is more sensitive to changes than to states (prospect theory)* overweights low probabilities* shows diminishing sensitivity to quantity (psychophysics)* responds more strongly to losses than to gains (loss aversion)* frames decision problems narrowly, in isolation from one another*

Characteristics of System 1: • generates impressions, feelings, and inclinations; when endorsed by System 2 these become beliefs, attitudes, and intentions • operates automatically and quickly, with little or no effort, and no sense of voluntary control • can be programmed by System 2 to mobilize attention when a particular pattern is detected (search) • executes skilled responses and generates skilled intuitions, after adequate training • creates a coherent pattern of activated ideas in associative memory • links a sense of cognitive ease to illusions of truth, pleasant feelings, and reduced vigilance • distinguishes the surprising from the normal • infers and invents causes and intentions • neglects ambiguity and suppresses doubt • is biased to believe and confirm • exaggerates emotional consistency (halo effect) • focuses on existing evidence and ignores absent evidence (WYSIATI) • generates a limited set of basic assessments • represents sets by norms and prototypes, does not integrate • matches intensities across scales (e.g., size to loudness) • computes more than intended (mental shotgun) • sometimes substitutes an easier question for a difficult one (heuristics) • is more sensitive to changes than to states (prospect theory)* • overweights low probabilities* • shows diminishing sensitivity to quantity (psychophysics)* • responds more strongly to losses than to gains (loss aversion)* • frames decision problems narrowly, in isolation from one another*

The social norm against stereotyping, including the opposition to profiling, has been highly beneficial in creating a more civilized and more equal society. It is useful to remember, however, that neglecting valid stereotypes inevitably results in suboptimal judgments. Resistance to stereotyping is a laudable moral position, but the simplistic idea that the resistance is costless is wrong. The costs are worth paying to achieve a better society, but denying that the costs exist, while satisfying to the soul and politically correct, is not scientifically defensible. Reliance on the affect heuristic is common in politically charged arguments. The positions we favor have no cost and those we oppose have no benefits. We should be able to do better.

There is voluminous evidence that exclusive reliance on heuristic processing tendencies of Type I sometimes results in suboptimal responding (Baron, 2008; Evans, 2007a; Gilovich, Griffin, & Kahneman, 2002; Johnson-Laird, 2006; Kahneman & Tversky, 1973, 1996, 2000; Koehler & Harvey, 2004; Nickerson, 2004, 2008; Nisbett & Ross, 1980; Tversky & Kahneman, 1974, 1983, 1986) and that such thinking errors are not limited to the laboratory (Ariely, 2008; Åstebro, Jeffrey, & Adomdza, 2007; Baron, 1998; Baron, Bazerman, & Shonk, 2006; Belsky & Gilovich, 1999; Berner & Graber, 2008; Camerer, 2000; Chapman & Elstein, 2000; Croskerry, 2009a, 2009b; Dawes, 2001; Hilton, 2003; Kahneman & Tversky, 2000; Lichtenstein & Slovic, 2006; Lilienfeld, Ammirati, & Landfield, 2009; Myers, 2002; Prentice, 2003; Reyna et al., 2009; Stewart, 2009; Sunstein, 2002, 2005; Taleb, 2001, 2007; Tavris & Aronson, 2007; Tetlock, 2005; Thaler & Sunstein, 2008; Ubel, 2000).

Brains with insufficient life experience have not had the chance to model the world into a few heuristics, and must instead try to reason their way to the right result, not unlike how psychopaths, who lack any moral intuitions, must reason their way through moral dilemmas. When teenagers are placed in a scanner and asked things such as whether it is a good idea to swim with sharks, they show substantially more frontal activation than adults, most of whom have learned over many years that swimming with sharks belongs in the “don't do” category without having to think much at all about it. That is, teenagers can reason, but their worldview is still too constricted to allow that reason to reliably result in rational outcomes.48 Of course, brains develop at rates that differ across individuals, just as some seventeen year olds have had more brain-tuning experiences than others. As a result, as all parents know, some teenagers are more responsible than others. Likewise, some adults are less responsible than others. Until neuroscience can tell us which brains are sufficiently responsible on an individual level, and indeed what “sufficiently responsible” is, the law must continue to do what humans have always done – make gross classifications based on categories rather than on individuals.

The VCs were prolific. They talked like nobody I knew. Sometimes they talked their own book, but most days, they talked Ideas: how to foment enlightenment, how to apply microeconomic theories to complex social problems. The future of media and the decline of higher ed; cultural stagnation and the builder’s mind-set. They talked about how to find a good heuristic for generating more ideas, presumably to have more things to talk about. Despite their feverish advocacy of open markets, deregulation, and continuous innovation, the venture class could not be relied upon for nuanced defenses of capitalism. They sniped about the structural hypocrisy of criticizing capitalism from a smartphone, as if defending capitalism from a smartphone were not grotesque. They saw the world through a kaleidoscope of startups: If you want to eliminate economic inequality, the most effective way to do it would be to outlaw starting your own company, wrote the founder of the seed accelerator. Every vocal anti-capitalist person I’ve met is a failed entrepreneur, opined an angel investor. The SF Bay Area is like Rome or Athens in antiquity, posted a VC. Send your best scholars, learn from the masters and meet the other most eminent people in your generation, and then return home with the knowledge and networks you need. Did they know people could see them?

Something, somewhere, somewhen, must have happened differently… PETUNIA EVANS married Michael Verres, a Professor of Biochemistry at Oxford. HARRY JAMES POTTER-EVANS-VERRES grew up in a house filled to the brim with books. He once bit a math teacher who didn’t know what a logarithm was. He’s read Godel, Escher, Bach and Judgment Under Uncertainty: Heuristics and Biases and volume one of The Feynman Lectures on Physics. And despite what everyone who’s met him seems to fear, he doesn’t want to become the next Dark Lord. He was raised better than that. He wants to discover the laws of magic and become a god. HERMIONE GRANGER is doing better than him in every class except broomstick riding. DRACO MALFOY is exactly what you would expect an eleven-year-old boy to be like if Darth Vader were his doting father. PROFESSOR QUIRRELL is living his lifelong dream of teaching Defense Against the Dark Arts, or as he prefers to call his class, Battle Magic. His students are all wondering what’s going to go wrong with the Defense Professor this time. DUMBLEDORE is either insane, or playing some vastly deeper game which involved setting fire to a chicken. DEPUTY HEADMISTRESS MINERVA MCGONAGALL needs to go off somewhere private and scream for a while. Presenting: HARRY POTTER AND THE METHODS OF RATIONALITY You ain’t guessin’ where this one’s going.

In the last few years I have been advocating a methodology of scientific research programmes, which solves some of the problems which both Popper and Kuhn failed to solve. First, I claim that the typical descriptive unit of great scientific achievements is not an isolated hypothesis but rather a research programme. Science is not simply trial and error, a series of conjectures and refutations. ‘All swans are white’ may be falsified by the discovery of one black swan. But such trivial trial and error does not rank as science. Newtonian science, for instance, is not simply a set of four conjectures—the three laws of mechanics and the law of gravitation. These four laws constitute only the ‘hard core’ of the Newtonian programme. But this hard core is tenaciously protected from refutation by a vast ‘protective belt’ of auxiliary hypotheses. And, even more importantly, the research programme also has a ‘heuristic’, that is, a powerful problem-solving machinery, which, with the help of sophisticated mathematical techniques, digests anomalies and even turns them into positive evidence. For instance, if a planet does not move exactly as it should, the Newtonian scientist checks his conjectures concerning atmospheric refraction, concerning propaga­tion of light in magnetic storms, and hundreds of other conjectures which are all part of the programme. He may even invent a hitherto unknown planet and calculate its position, mass and velocity in order to explain the anomaly.