Overhead, orange-billed toucans fly past, while troops of capuchin monkeys chatter nosily in the dense canopy.
The capuchin monkeys were upset, selfishly, when they didn't get the grapes that their neighbors received.
After training the monkeys to trade pebbles for slices of cucumber, the capuchin happily played the game.
The teams said the capuchin were more likely to take food from helpful people than "selfish" ones.
Sarah Brosnan, currently at Georgia State University, found that capuchin monkeys reacted dramatically to being treated unfairly.
Scientists from Stirling University and Kyoto University in Japan observed capuchin monkeys responded best to humans who were helpful to others.
But upon seeing that the other monkey has grapes, the capuchin monkey throws the next piece of cucumber that it is given back at the researcher.
In a 2008 study, de Waal and colleagues put two capuchin monkeys side by side and gave them a simple task to complete: Giving a rock to the experimenter.
In 1987, the bishop from a local Capuchin mission volunteered to reach out to one particularly reclusive tribe, the Tagaeri, who lived on land that another oil company wished to explore.
As observed in a popular video that de Waal showed in his TED talk, after receiving the first piece of cucumber, the capuchin monkey gives the experimenter a rock as expected.
During Friday's liturgy, the papal preacher, Capuchin friar Fr Raniero Cantalamessa, delivered a homily citing Franz Kafka's An Imperial Message to emphasise the of difficulty of getting the important message of Christ to the worldly.
Researcher Keith Chen at the Yale School of Organization and Management grabbed headlines last summer when he released a study showing that capuchin monkeys could be trained to use shiny metal disks just like human money.
"My underlying goal is to determine what aspects of our economic behavior are innate, deep in the brain and conserved over time, " says Chen, an economist who teamed up with Yale psychologist Laurie Santos to study capuchin behavior.
If she's going to say yes, she's going to say yes (or ... there's always the other possibility), and a cast of thematically dressed thousands and dancing capuchin monkeys, with celebrity cameos, won't top the fact that the person she loves has just floated the notion of spending eternity together.
应用推荐