Apes also get emotional over games of chance
|These chimpanzees were study subjects at the Tchimpounga Chimpanzee Sanctuary in Pointe Noire, Republic of Congo [Credit: Alexandra Rosati]|
The apes in this study faced two different types of problems: one where they made choices about whether to wait to obtain larger rewards, and one where they made choices about whether to take a chance to obtain a high-quality treat, but risk obtaining a non-preferred food item if their gamble did not pay off.
The scientists found that both species displayed emotional responses to the outcome of their choice, but chimpanzees were more patient and likely to take risks than bonobos. When their choice yielded the less preferred outcome, both species displayed negative emotional responses including vocalizations similar to pouts and moans, scratching, and banging--a type of tantrum thought to reflect anger in apes.
In the risky choice task, the apes even tried to switch their choice after the fact when they realized they had made a losing gamble, but never did so when their risk-taking paid off. Some of the emotional and motivational responses displayed by the apes were species-specific while others reflected individual differences in the animals.
Based on their results, the authors conclude that apes do exhibit emotional responses to decision-making, like humans. They add that further research is needed to determine whether these emotional responses to outcomes can change the apes' future choices and decisions.
Source: Public Library of Science [May 29, 2013]