Chimpanzees ( Pan troglodytes) Are More Averse to Social Than Nonsocial Risk.

Social risk is a domain of risk in which the costs, benefits, and uncertainty of an action depend on the behavior of another individual. Humans overvalue the costs of a socially risky decision when compared with that of purely economic risk. Here, we played a trust game with 8 female captive chimpanzees ( Pan troglodytes) to determine whether this bias exists in one of our closest living relatives.

Intranasal Oxytocin Failed to Affect Chimpanzee () Social Behavior.

Oxytocin has been suggested as a treatment to promote positive social interactions in people with Autism Spectrum Disorders (ASD). However, it is difficult to test this effect outside of the laboratory in realistic social situations. One way to resolve this issue is to study behavioral changes in closely related species with complex social relationships, such as chimpanzees.

Discrimination of emotional facial expressions by tufted capuchin monkeys (Sapajus apella).

Tufted or brown capuchin monkeys (Sapajus apella) have been shown to recognize conspecific faces as well as categorize them according to group membership. Little is known, though, about their capacity to differentiate between emotionally charged facial expressions or whether facial expressions are processed as a collection of features or configurally (i.e.

Flexibility and persistence of chimpanzee (Pan troglodytes) foraging behavior in a captive environment.

As a result of environmental variability, animals may be confronted with uncertainty surrounding the presence of, or accessibility to, food resources at a given location or time. While individuals can rely on personal experience to manage this variability, the behavior of members of an individual's social group can also provide information regarding the availability or location of a food resource. The purpose of the present study was to measure how captive chimpanzees individually and collectively adjust their foraging strategies at an artificial termite mound, as the availability of resources provided by the mound varied over a number of weeks.

Hand preferences for coordinated bimanual actions in 777 great apes: implications for the evolution of handedness in hominins.

Whether or not nonhuman primates exhibit population-level handedness remains a topic of considerable scientific debate. Here, we examined handedness for coordinated bimanual actions in a sample of 777 great apes including chimpanzees, bonobos, gorillas, and orangutans. We found population-level right-handedness in chimpanzees, bonobos and gorillas, but left-handedness in orangutans.

Brief communication: Captive gorillas are right-handed for bimanual feeding.

Predominance of right-handedness has historically been considered as a hallmark of human evolution. Whether nonhuman primates exhibit population-level manual bias remains a controversial topic. Here, we investigated the hypothesis that bimanual coordinated activities may be a key-behavior in our ancestors for the emergence and evolution of human population-level right-handedness.