Chimpanzees make judgments about the actions and dispositions of strangers by observing others’ behavior and interactions in different situations. Specifically, chimpanzees show an ability to recognize certain behavioral traits and make assumptions about the presence or absence of these traits in strangers in similar situations thereafter. These findings, by Dr. Francys Subiaul - from the George Washington University in Washington DC - and his team, have just been published online in Animal Cognition, a Springer journal.
Character judgments are an essential feature of cooperative exchanges between humans, and we use them to predict future behavioral interactions. A system for attributing reputation is therefore expected in any species which needs to assess the behavior of others and to predict the outcomes of future interactions. Chimpanzees have sophisticated social skills and there is evidence that primates eavesdrop and benefit from third-party interactions. Could they have a system for forming reputation judgments across a wide variety of contexts like humans"
In a series of three experiments, Dr. Subiaul and colleagues looked at whether chimpanzees learn the reputation of strangers indirectly by observation, or by first-hand experience. Seven chimpanzees observed unfamiliar humans either consistently give (‘generous’ donor) or refuse to give (‘selfish’ donor) food to either a familiar human recipient or another chimp.
In the first experiment, after observing humans either give or refuse food to familiar humans, chimps were in turn given the opportunity to gesture to either the ‘selfish’ or the ‘generous’ human.
There was no marked preference for either donor. However, in a second experiment, the researchers evaluated whether prolonged observation and first-hand experience would allow chimps to generalize this social rule—pertaining to the reputation of strangers—to new humans. In this experiment, the chimpanzees showed a strong preference for the new generous donor. They were able to predict which new donor was generous, based entirely on observation.
In a third experiment, chimpanzees (rather than humans) were the recipients of either ‘selfish’ or ‘generous’ acts. The results of this last experiment replicated the results of the second experiment in a new context and using novel ‘generous’ and ‘selfish’ acts, demonstrated that chimpanzees are flexible and astute social problem-solvers, capable of attributing reputation to strangers by eavesdropping on interactions between others.
The authors conclude that their results demonstrate chimpanzees’ ability “to infer stability in an individual’s character or behavior over time through observation – an inference that underlies the ability to make reputation judgments…This ability may have served as a catalyst to the evolution of various uniquely human traits such as shared intentionality, language and reasoning.”
Reference: Subiaul F et al (2008). Do chimpanzees learn reputation by observation Evidence from direct and indirect experience with generous and selfish strangers. Animal Cognition (DOI 10.1007/s10071-008-0151-6)
Source: Springer
Related stories:
Simian foamy virus found to be widespread among chimpanzees
Researchers in Cameroon, the Democratic Republic of Congo, France, Gabon, Germany, Japan, Rwanda, the United Kingdom, and the United States have found that simian foamy virus (SFV) is widespread among wild chimpanzees throughout equatorial Africa. Details are published July 4th in the open-access journal
PLoS Pathogens.
Great apes think ahead
Apes can plan for their future needs just as we humans can – by using self-control and imagining future events. Mathias and Helena Osvath's research, from Lunds University Cognitive Science in Sweden, is the first to provide conclusive evidence of advanced planning capacities in non-human species. Their findings are published online this week in Springer's journal,
Animal Cognition.
Infant play drives chimpanzee respiratory disease cycles
The signature boom-bust cycling of childhood respiratory diseases was long attributed to environmental cycling. However, the effect of school holidays on rates of social contact amongst children is increasingly seen as another major driver. New research on chimpanzees suggests that this effect of social connectivity on disease cycling may long predate attendance of children at schools, with chimpanzee infant mortality rates cycling in phase with rates of social play amongst infants.
Researchers find human virus in chimpanzees
After studying chimpanzees in the wilds of Tanzania's Mahale Mountains National Park for the past year as part of a National Science Foundation (NSF) grant, Virginia Tech researcher Dr. Taranjit Kaur and her team have produced powerful scientific evidence that chimpanzees are becoming sick from viral infectious diseases they have likely contracted from humans.
Did walking on 2 feet begin with a shuffle?
Somewhere in the murky past, between four and seven million years ago, a hungry common ancestor of today’s primates, including humans, did something novel. While temporarily standing on its rear feet to reach a piece of fruit, this protohominid spotted another juicy morsel in a nearby shrub and began shuffling toward it instead of dropping on all fours, crawling to the shrub and standing again.
Surgeon operates to rescue chimp with rare deformity
An orthopaedic surgeon at the University of Liverpool has performed a groundbreaking operation on a chimp in Cameroon to correct a deformity more commonly seen in dogs.
Researchers find first conclusive evidence of Alzheimer's-like brain tangles in nonhuman primates
Researchers at the Yerkes National Primate Research Center, Emory University, have discovered the first conclusive evidence of Alzheimer's-like neurofibrillary brain tangles in an aged nonhuman primate. The unprecedented finding, described in the online issue of the
Journal of Comparative Neurology, has the potential to move the scientific community one step closer to understanding why age-related neurodegenerative diseases, such as Alzheimer's disease, are uniquely human and seem to never fully manifest in other species--including our closest evolutionary relative, the chimpanzee.
Slowly-developing primates definitely not dim-witted
Some primates have evolved big brains because their extra brainpower helps them live and reproduce longer, an advantage that outweighs the demands of extra years of growth and development they spend reaching adulthood, anthropologists from Duke University and the University of Zurich have concluded in a new study.