Predictably Irrational summary

Few things get people to behave as irrationally as the word “free.” For example, people happily lug home useless free key chains from conferences, or buy two products they don’t need just because the third one is free.

Free is not just a price, but a powerful, almost irresistible emotional trigger.

How much would you be willing to pay for a nice bottle of wine? What about a box of Swiss chocolates?

Do you have the figures in mind?

At Duke University, getting tickets for basketball games is, to put it lightly, an ordeal. Students camp out for days in front of the stadium just to participate in a lottery for tickets.

Before the lottery, they are a fairly homogeneous group. They all stand an equal chance of winning a ticket and all have worked equally hard for that chance, so presumably they all value the tickets roughly equally. Yet, as soon as the lottery is over, the students are divided into two groups – those who won tickets and those who did not.

At one stage, both Pepsi and Coke claimed that consumers preferred the taste of their cola over the other.

But how could both of them truthfully say this? Was one lying?

Why would your mother be offended if you offered to pay her $50 for the Sunday dinner she lovingly prepared?

And why would most employees refuse to be paid in hugs by their employer?

Do you consider yourself an honest person? Would you rob a bank? Would you take a Coke from the communal fridge in the workplace if no one was looking?

Studies have shown that most people are a little bit dishonest. For example, when people took a math quiz with small monetary prizes as rewards, it was found that given the chance to grade themselves, most people would cheat by slightly exaggerating their own performance. Encouragingly though, the amount of cheating did not increase when the chances of being caught were lessened. Even when it was impossible to get caught, people did not begin to cheat massively.

Have you ever decided to start living more frugally, eating more healthily or watching less TV, only to find yourself mere days later buying something you don’t need, stuffing potato chips in your mouth or spending an entire Sunday watching TV?

Sometimes human existence seems analogous to the story of Dr. Jekyll and Mr. Hyde. The cool, rational, reasonable side of us knows what we should do, but then the impulsive, uncontrollable side takes over and does the exact opposite.

In 210 BC, after the Chinese commander Xiang Yu had ferried his army across the Yangtze River, he set fire to his own ships. He did this to show his troops that retreat was not an option. In response, they fought so ferociously that they won nine battles consecutively.

This story has become famous because deliberately closing an available option runs counter to our natural instincts. We humans try to keep our options open as much as possible: in our education, our careers and our choice of romantic partner.