Técnicas e instrumentos para la recolección de datos

In Prelude to Foundation, the first prequel to Asimov’s Foundation Trilogy, a young Hari Seldon delivers a talk at a mathematics con- ference on the planet Trantor, capital world of the Galactic Em- pire. Seldon’s talk describes his idea of predicting the future via the math of psychohistory, a science that he had just begun to develop. Naturally the emperor receives word of this talk (in the galactic future, politicians pay more attention to science than they do today) and invited Seldon to an audience.

“What I have done,” Seldon told the emperor, “is to show that, in studying human society, it is possible . . . to predict the future, not in full detail, of course, but in broad sweeps; not with cer- tainty, but with calculable probabilities.”6

actually predict the future just yet, that he merely had the germ of an idea about how to do so if the mathematics could be prop- erly developed. Seldon, in fact, was skeptical that he would ever succeed.

“In studying society, we put human beings in the place of subatomic particles, but now there is the added factor of the hu- man mind,” Seldon explained. “To take into account the various attitudes and impulses of mind adds so much complexity that there lacks time to take care of all of it.”7

In fact, Seldon pointed out, an effective psychohistory capable of predicting the galactic future would have to account for the interacting human variables on 25 million planets, each containing more than a billion free-thinking minds. “However theoretically possible a psychohistorical analysis may be, it is not likely that it can be done in any practical sense,” he admitted.8

By displeasing the emperor with such pessimism, Seldon soon found himself a fugitive, roaming from one sector to another on the planet Trantor—the urban sector of the Imperial capital, a university town, a farming region, an impoverished mining center. By the end of the book Seldon realized that Trantor was a micro- cosm of the galaxy, home to hundreds of societies each with their own mores and customs. That was his solution to achieving a sci- ence of psychohistory! He didn’t have to analyze 25 million worlds; he could understand the variations in human behavior by using Trantor itself as a laboratory.

Toward the end of the 20th century, Earth-bound anthropolo- gists independently arrived at a similar scheme for analyzing hu- man social behavior. By playing the ultimatum game (and some variants) in small, isolated societies around the planet, those scien- tists have found that human nature isn’t so universal after all. Col- lege students in postindustrial society, it turns out, are not perfectly representative of the entire human race.

This worldwide game-playing project began after anthropolo- gist Joe Henrich, then a graduate student at UCLA, tried out the ultimatum game with the Machiguenga farmers of eastern Peru in 1996. The rules were the same as with college students: One player

is given a sum of money and must offer a share of it to the second player. The second player may either accept the offer (and the first player keeps the rest) or the second player may reject the offer, in which case all the money is returned and neither player gets any- thing.

By the time Henrich tried the game in Peru, it had been widely played with college students, who usually make offers averaging more than 40 percent of the pot. Such offers are routinely ac- cepted. Sometimes lower amounts would be offered, but they would usually be rejected. Among the Machiguenga, though, Henrich observed that lower amounts were routinely offered—and usually accepted.

“We both expected the Machiguenga to do the same as every- body else,” UCLA anthropologist Robert Boyd told me. “It was so surprisingly different that I didn’t know what to expect anymore.”9 Could it be that the Machiguenga actually understood the rational-choice rules of game theory, while everybody else in the world let emotions diminish their payoffs? Or would other iso- lated cultures behave in the same way? Soon Henrich, Boyd, and others acquired funding from the MacArthur Foundation, and later the National Science Foundation, to repeat the games in 15 small- scale societies on four continents. The results were utterly baffling. From Fiji to Kenya, Mongolia to New Guinea, people played the ultimatum game not just the way college students did, or the way economic theory dictated, but any way they darn well pleased.

In some cultures, like the Machiguenga, low offers were typi- cal and were often accepted. But in other cultures, low offers were frequently made but typically rejected. In a few cultures the offers would sometimes be extra generous—even more than half. But in some societies such generous offers were likely to be refused. Among other groups, rejections almost never occurred, regardless of the size of the offer.10

“It really makes you rethink the nature of human sociality,” Henrich, now at Emory University in Atlanta, told me. “There’s a lot of variation in human sociality. Whatever your theory is about human behavior, you have to account for that variation.”11