Predictably Irrational

The book opens with a personal tragedy. At eighteen, in Israel, an exploding magnesium flare leaves 70% of Ariely's body covered in third-degree burns, and he spends three years in hospital in bandages. Every day the nurses ripped the bandages off quickly, believing that a short, intense pain is better than a long, mild one. Ariely later tests this in the lab and finds the opposite: when the pain is milder but longer, people experience less total suffering. His conclusion is the core idea of the book — the nurses were neither malicious nor incompetent, yet years of experience did not correct such a systematic error. Our mistakes are not random; they are predictable.

Chapter 1 begins with a subscription offer from The Economist: web only for 59 dollars, print only for 125, print and web together — also 125. Nobody picks the second option, so why is it there? When Ariely gives these options to 100 students at MIT Sloan, 16 choose the web and 84 the bundle. Remove the «useless» option and the picture flips: 68 choose the web and only 32 the bundle. He calls this the decoy: we cannot judge value in absolute terms, so we compare with what sits next to it, and the option that is easiest to compare wins.

The chapter develops the idea with everyday examples: the TV salesman places the model he wants to sell in the middle; a restaurant adds an expensive dish no one orders so that the second most expensive one sells well; a home bread maker only starts selling once a second model, 50% more expensive, is placed beside it. The most striking experiment uses photographs: students see two normal faces plus a slightly «uglified» Photoshop version of one of them, and about 75% of choices go to the «good» twin of the distorted face. The author draws a tongue-in-cheek dating tip from this — take along a friend who looks like you but is slightly less attractive — and in an appendix admits how this advice backfired in one reader's life.

The second half of the chapter turns to the dark side of relativity. A young employee earning 300,000 dollars a year is unhappy because colleagues at the next desks earn 310,000. In 1993 US regulators required companies to disclose executive pay in the hope of restraining it; instead executives began comparing themselves with one another, and the gap between the average CEO and the average worker grew from 131 times to about 369 times. Tversky and Kahneman's famous question appears too: we will drive 15 minutes to save 7 dollars on a 25-dollar pen, but not to save the same 7 dollars on a 455-dollar suit. Ariely's remedy is to shrink our circles of comparison, citing an entrepreneur who sold his Porsche for a Prius because «if you have a Boxster you want a Ferrari».

On the basis of the part read, the book's strength is clear: every idea is shown through a simple, memorable experiment and immediately tied to everyday life. The Turkish translation reads smoothly, though there are some typos and poorly printed graphs. The book is a product of 2008, and that matters: for example, the Chapter 11 experiment in which recalling the Ten Commandments reduced cheating was not confirmed by a large later replication. A 2012 paper co-authored by Ariely, not included in this book, was retracted in 2021 after fabricated data were found (Ariely denies fabricating it). It is therefore wiser to read the book for its way of thinking and not to treat individual numbers as settled fact.

• A story-driven style that shows each idea through a lab or street experiment
• Humorous examples from the author's own life and from his students
• Small everyday takeaways at the end of each chapter