A group of researchers tested whether monkeys show a common human bias: the tendency to confuse the price of a good with its quality. Previous studies have shown that humans think wine labeled with an expensive price tag tastes better than the same wine labeled with a cheaper price tag. In other studies, people thought a pain killer worked better when they paid a higher price for it.
"We know that capuchin monkeys share a number of our own economic biases. Our previous work has shown that monkeys are loss averse, irrational when it comes to dealing with risk, and even prone to rationalizing their own decisions, just like humans," said Laurie Santos, a psychologist at Yale University and senior author of the study. "But this is one of the first domains we've tested in which monkeys show more rational behavior than humans do."
"Sticking a higher price tag on a bottle of wine shouldn't make it taste better, but-- surprisingly--it does," added Rhia Catapano, a former Yale undergraduate who ran the study as part of her senior honors thesis. "We wanted to see whether monkeys showed this same bias."
Santos and colleagues designed a series of four experiments to test whether capuchins would prefer higher-priced but equivalent items. They taught monkeys to make choices in an experimental market and to buy novel foods at different prices. Control studies showed that monkeys understood the differences in price between the foods. But when the researchers tested whether monkeys preferred the taste of the higher-priced goods, they were surprised to find that the monkeys didn't fall for the bias.
Santos and colleagues think that differences in the response of humans and capuchins could stem from the different experiences that monkeys and people have with markets and how they behave. "For humans, higher price tags often signal that other people like a particular good." Santos noted. "Our richer social experiences with markets might be the very thing that leads us-- and not monkeys-- astray in this case."