In order to avoid bias from items that might be more or less valuable in the environment the Hadza live in, the researchers constructed the experiments so that participants chose between items that had only cosmetic differences. Participants would be given either a package of cookies, with the option to trade it for a different flavor, or given a lighter, with the option to trade it for a different color. They also ensured that the participant knew that the variety he or she received at the start was a random choice, and varied whether the participant got to physically hold the item before given the option to trade it for another variety.
"We wanted to use both food and tools, as experiments with non-human primates show an endowment effect for the former but not the latter," Apicella said. "However, we saw that it didn't make a difference whether a person was choosing between cookies or lighters. The difference-maker was their relative level of isolation from modern life."
"The more isolated Hadza traded about 50 percent of the time which is what rational people should do," Azevedo said. People near the village traded about 25 percent of the time, which is much closer to the 10 percent we see with Western students."
"To make sure this wasn't a case of the more capitalistic people moving closer to the village, we also asked the people about their social networks," Azevedo said. "The percentage of people who named someone in a distant camp was very small. Quantitatively, it seems impossible that the difference in endowment effect between two camps could be explained by migration."
With that potential caveat accounted for, one explanation for the apparent lack of an endowment effect in the more isolated camps is that the bias is a learned behavior that comes with exposure to capitalistic societies. However, an alternative explanation
|Contact: Evan Lerner|
University of Pennsylvania