Irrationality by Stuart Sutherland [Book Summary – Review]


Humans are intelligent creatures. That basic reality has been a central presumption of scientists and philosophers and remains to be a thing we are taught from a little age, from the Enlightenment in eighteenth-century Europe.

Yet are we truly as intelligent as we believe?

Well, actually, we’re so much less reasonable in our daily practice than we might assume. Irrationality is part of our daily life and, it often goes wholly neglected, when we judge others because of their appearances, when we feel we need to obey our feeling, or when we resist changing our minds even if it goes against logic.

That review will show you what irrationality causes, how we are irrational in various circumstances, and what we can do to be more logical.


Buy this book from Amazon



Chapter 1 – Irrationality is more prevalent than people imagine and is the outcome of neglecting information. 


We tend to believe that humans are genuinely rational creatures, and the source of that opinion can be followed thousands of years back. From Aristotle’s contention that human is a “rational animal,” to Descartes’ remarkable declaration, “I think, therefore I am,” to Kant’s “have the courage to use your own reason,” a prevalent view during history has been that human beings are essentially rational.

But ultimately this may not be accurate.

The time we meet a new person, we usually try to resolve them in a second, grounded only on their appearances. This is extremely prevalent and also completely irrational since people usually transpire to act quite differently than they look. 

So, obviously, we are likely to be irrational – but what does this term really mean?

In sum, intentionally forming results that aren’t grounded on the information, is what irrationality means. So, it can be reasonable for a young boy to climb a tree for touching the moon. Yet if an adult astronomer, who knows how far away the moon is, performed the exact action, it would be completely irrational.



Basically, the extent of our knowledge has a role in deciding the rationality of our behaviors. However, even rational thinking is grounded on information, rational outcomes may also be incorrect. People have long thought that all swans are white, for instance; until Australia, the continent where black swans were common, was discovered, this was a perfectly rational presumption. 

That is an instance of how inadequate or incorrect information can cause wrong outcomes, in spite of logical thinking. Yet wrong rationality should not be confused with illogicality. Irrational thinking differs in a manner that it is intentional.

While doing the math, accidentally, forgetting to carry the one will create a mistake – however, it wouldn’t be the outcome of irrationality. Irrationality would be ignoring information in spite of its abundant presence, like considering someone’s not suitable for work even though his resume fits the requirements perfectly.

So, making an irrational decision requires an intentional act. But why do people do this? 

Chapter 2 – Irrationality has an effect both on individuals and organizations.

Humans make unreasonable decisions for numerous reasons, and that propensity bothers individuals and also large organizations. People tend to deceive their sense of truth for perpetuating irrational acts and ideas, as far as individuals are concerned.

After making a decision, we usually glorify our decision because we don’t want to face the chance of it being faulty. We tend to lower our minds about the choice we didn’t make, in a similar way. 

Actually, researches have shown that while teenage girls are asked to rate a series of albums and afterward prefer one of the albums that they gave an alike rating, girls’ rating of the record chosen in the second part of the study was considerably higher than the one they chose it over.

However, deceiving our sense of reality is not the only way we can behave illogically; we like sticking to irrational behavior and ideas too.

In the stock market, the place people feel an irrational compulsion to hold an investment that has fallen in value and shows no signs of increasing again, this happens all the time. Continuing to the stock if it was advantageous and letting go of it if not, the obvious rational selection would be, in this situation.

So those are the ways individuals are influenced by illogicality – what about bigger groups?



A prevalent way that irrationality can arise in organizations is via formations that contrast with organizational aims. Actually, organizational formations usually promote selfish acts that serve individuals at the cost of the whole. 

Bonus payments, at investment banks, lead to boost bankers to place risky bets that could cause significant gains and, as a result of that, great bonuses. However, bankers are infrequently kept responsible for their poor bets on risky assets; as a whole, the organization has to carry the weight of its faults. 

In an organization, in the financing of departments, a different example can be seen. Usually, the amount of money allocated to a particular department, regardless of how the money was spent, depends on how much had given in the previous year. That sort of policy does not promote organizational well-being but, over-spending. 

Chapter 3 – The time and the way we get information is an important element in our irrationality. 

As you know, rather than a shark attack while swimming in the ocean, you have more likelihood to die in a car accident. Still, a film about a man-eating shark, the 1975 movie premiere of Jaws, let an obvious decline in sea swimmers in California. 

The scared Californians were surrendering to something known as the error of availability, where people were illogically neglecting known facts and giving attention to the information that had the greatest impact on them or came to their minds easily. To rephrase it, what is directly “available”. 

Our propensity to the availability error, and accordingly irrationality, rises when we’re faced with emotionally loaded information. The annual number of deaths from strokes is 40 times higher than those caused by accidents, for example; yet, lots of people still think that they have more chance to die in an accident since the media regularly features accidents like plane crashes that are highly emotionally loaded.



Actually, emotionally strong information which we’ve lately been faced with gets into our minds more quickly than other information. As a consequence, people are more probable to watch a movie that they’ve watched the trailer of it rather than a movie they’ve just read about.

Emotionally loaded illustrations are more “available” for our minds than basic text. 

The availability error may lead to all kinds of other irrational acts too. A striking instance is a situation known as the primacy error, which is the state that we form irrational ideas grounded on a first impression. Since our first impression is the thing that comes directly to our minds, we do this.

Furthermore, another instance is called the halo effect: the time a person has a remarkable good feature, we directly assume they have other good features as well. We are likely to think that people with good appearances are also clever, for instance.

Chapter 4 – Doing a thing that is socially expected and announcing decisions publicly, may cause an irrational act.

Following social norms is usually one of the most logical things you can do. Driving on the correct side of the street in order to avoid a car accident makes sense, for example. However, following social norms can also cause irrational acts.

Psychologist Solomon Asch showed that subjects give irrational decisions only for adapting to what society demands, for instance. He did this by showing two cards to his search subjects: the first one had one line on it and the second one had the same line as two others, one is considerably longer and the other is shorter than the first line.

He asked the participants who sat in a circle, to choose a line on the second card that was the equal height as that on the first one. Very interestingly, lots of participants changed by copying the response given by an assistant placed by the psychologist, and it turned out to be wrong. 

And in the real world, people always hold onto decisions that are announced publicly, even though they’re irrational. Actually, people have more likelihood to hold onto decisions that they publicly stated rather than those made in private.



In the final, it’s socially normative doing things we said we will. Therefore, when we take a wrong decision, instead of admitting that we changed our minds, we irrationally struggle to save ourselves.

Consider various studies by advertisement organizations that found out that foreigners who publicly state their buying of goods are more probable to really do it than those who have written their aims in private. 

That trend can create something named the boomerang effect, which states that once a powerful opinion is challenged, it becomes even more powerful. If a person strongly commits to an irrational faith by publicly announcing it, challenging their statement can make it even more powerful since the person in the subject will dig in their heels in order to save themselves, for example. 

Chapter 5 – It is irrational to give awards, and lack of choice leads to irrational acts.

Everyone loves rewards, and it probably looks like giving them is a rational way to support people. However the exact reverse is true: physical rewards are truly pretty disheartening, while spoken praise might be a good motivator because it can be internalized by the receiver and keep motivating them for times to come. Actually, rewards do not motivate people really to perform better, and accordingly, giving them is completely irrational.

In a study with students, researchers asked participants to write headlines for university newspapers. They gave money to one group while did not to the other. Finally, students who get nothing wrote more headlines, which shows that the monetary reward motivation caused worse performances. 

Fostering a want for self-improvement is so much better motivator than simple rewards. It has been confirmed that the best way of learning for students is through their teachers’ criticisms as helping them improve. Similarly, the more particular the comments, the more possible students are to be supported in their education.



Another thing that serves to irrational acts is not giving the chance to choose. An experiment confirmed that through giving ten-year-old kids a toy – but they gave their toys in different ways:

In both sample groups, they offered each individual kid two toys, one of them was the known favorite of the given kid. In the first group, the experimenter would give the child the two of their favorites, but at the same time say that the two toys looked identical to him and that he preferred that toy for the child without a reason in specific.

That group of kids liked their favorite toy much less than they had earlier, and less than other kids who were permitted to freely choose without the experimenter’s idea, their favorite toy. 

That is to say, the kids changed their opinion of their favorite toy, irrationally, just because someone else chose it instead of them – and apparently, did it randomly.

Chapter 6 – Rejecting information to sustain our beliefs and emotions can cause us to behave irrationally.

It’s prevalent for logic to be placed with emotions, and thus, it’s not really surprising that the latter is firmly tied to irrational acts. We can admire our partner so much that we think she’s the best person in the world or can run away from doctors because we’re scared of seeing we’re ill, for example. In sum, emotions make us act irrationally since they impact our worldview.

However, feelings and emotions are not the same. We may feel cold or tired; Emotions, on the other hand, are a combination of certain feelings in our trend to think and behave in particular styles.

Like many other emotions, stress, depression, and jealousy make us behave irrationally too since they blur our aspect. While optimistic people can usually focus on the positive side of things, depressed people tend to perceive the world much more negatively. 



Additionally, any type of powerful emotion holds us back from focusing on logical decision making and make it hard to think options, so causing irrational acts. An experiment gave participants a word and asked them to choose from a list of six others its anagram. 

Some of the participants performed much worse since they were put under stress with the warning of electric shock, than others who weren’t threatened. They scanned the options in a less concentrated way, made less right choices, and were four times more likely not to consider their choice before deciding. 

Therefore, emotions let irrational thinking – yet, so does not looking for conflicting proof to sustain our beliefs. Actually, instead of critiquing them and seeing if they actually hold up, which obviously would be a more logical thing to do, people usually look up support for their beliefs.

One research proved that we want confirmation of our ideas even though they are hostile to themselves: students who thought negative things about themselves chose to share rooms with people who also had negative thoughts about them. 

Chapter 7 – Irrationality holds us back from accurately judging correlations and cause-and-effect relationships.

Times that scientists couldn’t find a connection between smoking and lung cancer wasn’t long past. Actually, the correlation between the two had not noticed for ages before the scientists Richard Doll and Richard Peto published specific statistics in the 1970s.

So how could people not find this correlation?

Well, the incapacity to see links between events – or the tendency to see links that don’t exist – is an outcome of irrationally neglecting numbers and statistics, most of the time. Yet notwithstanding getting the numbers, we still make mistakes about connections between events each day. 

A cause for that is the trend to confuse the reasons and outcomes of events. Surveys have shown that people usually assume it’s more possible for a mother with blue eyes to have a daughter with the same color eyes rather than for a daughter with blue eyes to have a mother with blue eyes, for example. Clearly, that is illogical since the possibility is precisely the equal, the data is only phrased in a different way.



Yet finding a cause-and-effect connection while none exists is a big problem too. That kind of irrationality is named as an illusory correlation. We frequently see wrong cause-and-effect connections via connecting similar events or ideas, for instance. For example, until the late eighteenth century, it was believed that the bright yellow herb turmeric was curing the yellowing of the skin and eyes, jaundice. 

A different good example of this type of irrational link is psychoanalysis. That area tends to make wrong links, like the connection between humans breastfeeding during our babyhood and after adult business with the mouth as stated by kissing, smoking, or speaking very much. 

And this is not the single way psychoanalysis can fall prey to wrong cause and effect relationships. Psychoanalysts tend to connect their patients’ recovery to their treatment in a wrong way too; studies have shown that placebo methods that have a practitioner see a patient, listen and make supportive sounds without offering any convenient treatment, work quite well too, or better than actual psychoanalysis. 

Consequently, just because two events occur at the same time does not mean that one is the cause of the other. 

Chapter 8 – Intuition and overconfidence cause irrational decisions.

It doesn’t matter the task we have is accurately estimating the size of a parking lot, enough time for boiling an egg, or the advantages of a possible hire, our intuition may usually prove wrong. We are likely to trust our judgments and our own instincts too much.

A study showed that people who were 100 percent sure of their capacity to spell particular words, truly just spelled 80 percent of them accurately, for example. A different questionnaire showed that 95 percent of British drivers thought they were better than the ordinary motorist, while many people believe they’ll survive longer than the average person.

Normally, this type of feeling of overconfidence is irrational, because it’s basically improbable that the large majority of anything is better than the standard. And that is an issue since overconfidence can cause a major problem. The fire at the Browns Ferry nuclear reactor in Alabama occurred after an overly confident technician who believes in his skills, checked an air leak with a candle, for instance. 



And relying too much on our intuition can pose alike issues since it leads us to take irrational decisions. For example, job interviewers rely on their intuition to evaluate the cognitive skills of the candidate in a face-to-face interview; that approach is completely irrational.

The case that candidates take a series of oral and spatial tests, would be much more logical. Instead, the trend to rely on intuition returns to the halo effect, the trend to see someone naturally good, grounded on a good feature such as good appearances or self-confidence.

Therefore, instead of relying on our intuition to make good choices, we should use actuarial forecasts. That simply means using information and formal mathematical analysis to form an opinion.

Chapter 9 – Statistical knowledge increases rationality.

So you have seen how people act irrationally in numerous ways; but is rationality truly that charming?

The truth is, being rational is not that significant in the personal sphere as your personal preferences such as eating pasta or rice for dinner aren’t particularly significant. Plus when they are more significant, such as when picking a profession, rationality has many unexplored elements that just marginally raise the possibility of a successful result.

However, irrationality has a significant effect on society, whether in engineering or medicine. 

Then how can you be more logical? 

Thanks to the power of statistics. It’s no coincidence that all of the economics, psychology, and medical students learn fundamental statistics: consciousness about this area may reduce your odds of making wrong, irrational choices strongly.

A study asked subjects if a big hospital that averaged 45 births per day or a smaller one with an average of 15 births per day would see more days within a duration of a year on which 60 percent of the babies born were boys, for example. People presumed that the number of days would be equal for both hospitals, but some information about statistics shows that the smaller hospital is more probable to have days with 60 percent male deliveries, quickly. Why? 



The more frequently you repeat a random experiment where different events occur with known probabilities, the more likely the frequency of the events occurring found will match their actual frequency. That is named the law of large numbers since the larger the example, the more probable the right frequency of events is to occur within it. Hence, a 50-50 separation between male and female deliveries is more possible in the bigger hospital.

And statistics are not only good for this – they can develop rationality while trying to evaluate the outcomes of a decision as a result of your want for it and its probability of happening too. That is named utility theory and it’s the most solid approach to make rational choices as it considers both the possibility of a consequence and its charm.

Chapter 10 – Evade irrationality through paying attention to how the questions are phrased and writing the pros and cons while making decisions. 

While knowledge of statistics can assist you to make more rational choices, particularly when it comes to important and complicated problems, it’s not practical to use so much time making calculations. Therefore, here are some easier methods to evade irrationality.

A way is to realize that the style of a question is phrased can irrationally impact your answer. In a study, certain subjects were asked if they’d rather save 200 people from an imaginary fatal disease, or try to save 600 people with a 33 percent probability of achievement, for instance. To decide between the risk of letting 600 people die with a chance of 67 percent that they would die, or letting 400 people die for assured, was asked to a different group.

The two groups decided on completely different – however, the two questions were actually asking the exact thing, just expressed in a different way.

A comparable leaning can be seen in questions including ranges. When asked for deciding the number of headaches one has per week from 1-5, 6-10, and so on, or to rate our happiness with a good or service on a scale that involves “dissatisfied”, “satisfied”, “very satisfied” and “extremely satisfied”, people will likely to prefer one of the two middle selections negligent of whether it shows their true opinions. 



Knowledge of question prejudice is the answer to evading irrationality. Though different strategy is just to list the pros and cons while making complex choices. Above all, humans can only remember a definite number of thoughts at the same time; Making a list like that will ease you to make more rational decisions and avoid forgetting significant information. 

Noting your thoughts prevents information overload for your brain and hence the possibility of bad choice making. It was said that Even Charles Darwin used this way while trying to choose whether to marry or not! 

Irrationality by Stuart Sutherland Book Review

Most of the time people are likely to be irrational and that can negatively influence us. We can get better consequences through developing our rational decision-making skills, which rely on a trading hunch for statistical ways, evaluating the pros and cons of a condition, and taking all possible information into account.

Do not rush when it is about important decisions.

While there are numerous decisions to make, it can be a good idea to keep careful thinking for situations that are really important. Just be sure to get enough time to think it over and behave rationally when you are faced with a significant decision. Above all, an irrational slide could produce serious outcomes! 



Download Pdf


https://goodbooksummary.s3.us-east-2.amazonaws.com/Irrationality+by+Stuart+Sutherland+Book+Summary+-+Review.pdf


Download Epub


https://goodbooksummary.s3.us-east-2.amazonaws.com/Irrationality+by+Stuart+Sutherland+Book+Summary+-+Review.epub


Audiobook


Savaş Ateş

I'm a software engineer. I like reading books and writing summaries. I like to play soccer too :) Good Reads Profile: https://www.goodreads.com/user/show/106467014-sava-ate

Recent Content