You Are Not So Smart: Why You Have Too Many Friends on Facebook, Why Your Memory Is Mostly Fiction, and 46 Other Ways You're Deluding Yourself

by David McRaney

Before you hear about the public goods game, you need to understand the tragedy of the commons. The idea comes from a 1968 essay by geologist Garrett Hardin that suggested you aren’t very good at sharing. Imagine a giant lake filled with fish. You and three others are the only people who know about it. You all agree to take just as many fish from the lake as you need to eat. As long as everyone takes just what he or she needs, the lake will stay full of fish. One day, you happen to notice one of the others has started taking more than he or she needs and is selling the extra fish in a nearby town. Eventually that person has a better fishing rod than you. What do you do? If you start overfishing too, you will also be able to get a better rod, maybe even a boat. Maybe you could partner up against the cheater. Maybe everyone will just start taking as many fish as desired. Maybe you could just tell the world about the lake. All of these scenarios will probably lead to the ruin of the common good. If you do nothing, the lake will still be able to support you and the other two, but the cheater wins. Anger over unfair situations is something you can’t help but feel. In situations like the imaginary lake above, in an effort not to fall behind, everyone loses. A big holiday meal, for example, can become a zero-sum game if everyone piles a plate, but if everyone takes only what he or she needs, everyone wins. The tragedy of taking from a common good is over time the common good will...