The Economist once ran a subscription ad with three prices. Web only, fifty-nine dollars. Print only, one hundred twenty-five. Print and web, also one hundred twenty-five. The middle option is absurd and nobody buys it. Ariely showed the ad to a hundred MIT students and most took the bundle. Then he deleted the useless middle option, showed it to another hundred, and the majority switched to the cheap web-only plan. The decoy nobody wanted was steering the entire decision.
Predictably Irrational runs on demonstrations like that, dozens of them, each built to catch a specific place where the standard story of the rational chooser falls apart. Ariely has students write down the last two digits of their Social Security numbers, then bid on wine and chocolate, and the high-digit students bid several times more. He offers a Lindt truffle at fifteen cents against a Hershey's Kiss at one cent, drops both prices by a penny, and the free Kiss wipes the truffle out. He asks people to do a small favor, then offers a small payment for the same favor, and the payment makes them work less. Chapters are short and self-contained. The prose is a lecture-hall voice, jokey, light on math, heavy on setup and punchline.
The practical carryover is narrower than the sales-and-marketing crowd claims. Most of these effects describe a trap you are already standing in rather than a lever you can pull, and Ariely says so; knowing about a bias barely dents it. What survives contact with Monday morning is small and still worth doing. Strip the decoy out of any choice you present, and look for one planted in a choice presented to you. Set deadlines with real costs instead of trusting your future self, which is what his own students did when they beat the class given a single end-of-term due date. Think hard before attaching money to something that has been running on goodwill, because the price tag replaces the goodwill instead of adding to it. And treat the honesty chapters as the softest ground here. That corner of the research has had a rough decade, Ariely's own studies included.
Why you should read
- Fans of Freakonomics and Thinking, Fast and Slow
- Readers who want an experiment behind every claim
- Anyone who prices, sells, or negotiates for a living
- Curious readers with no economics background
What to expect
- Short chapters, one bias and one study each
- Conversational lecture-hall tone, almost no math
- Findings that describe the trap more than the escape
- Easy to read in pieces over a week
The experiment that sticks is the one with the doors. Ariely built a simple computer game where three doors pay out money, and any door left unclicked long enough starts shrinking and eventually vanishes. Players could have parked on the best-paying door and cleaned up. Instead they burned click after click, and real earnings, darting back to keep dying doors alive. Nobody wanted those doors. They wanted them open. Read the rest for the pricing tricks; that chapter follows you into decisions the book never mentions.