Do chimpanzees (Pan troglodytes) attribute preferences to virtual competitors?

Many animal species live in multi-level societies regulated by complex patterns of dominance. Avoiding competition with dominant group-mates for resources such as food and mates is an important skill for subordinate individuals in these societies, if they wish to evade harassment and aggression. Chimpanzees (Pan troglodytes) are an example of such a species.

Chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) chase prey around obstacles in virtual environments.

Apes require high volumes of energy-rich foods that tend to be patchily distributed, creating evolutionary pressures for flexible and complex cognition. Several species hunt mobile prey, placing demands on working memory and selecting for sociocognitive abilities such as predicting prey behavior. The mechanisms by which apes overcome foraging and hunting challenges are difficult to elucidate.

Training primates to forage in virtual 3D environments.

Virtual environment software is increasingly being employed as a non-invasive method in primate cognition research. Familiar and novel stimuli can be presented in new ways, opening the door to studying aspects of cognition in captivity which previously may not have been feasible. Despite the increased complexity of visual input compared to more traditional computerised studies, several groups of captive primates have now been trained to navigate virtual three-dimensional environments.

Bo-NO-bouba-kiki: picture-word mapping but no spontaneous sound symbolic speech-shape mapping in a language trained bonobo.

Humans share the ability to intuitively map 'sharp' or 'round' pseudowords, such as 'bouba' versus 'kiki', to abstract edgy versus round shapes, respectively. This effect, known as sound symbolism, appears early in human development. The phylogenetic origin of this phenomenon, however, is unclear: are humans the only species capable of experiencing correspondences between speech sounds and shapes, or could similar effects be observed in other animals? Thus far, evidence from an matching experiment failed to find evidence of this sound symbolic matching in great apes, suggesting its human uniqueness.

Chimpanzees (Pan troglodytes) show subtle signs of uncertainty when choices are more difficult.

Humans can tell when they find a task difficult. Subtle uncertainty behaviors like changes in motor speed and muscle tension precede and affect these experiences. Theories of animal metacognition likewise stress the importance of endogenous signals of uncertainty as cues that motivate metacognitive behaviors.

Using natural travel paths to infer and compare primate cognition in the wild.

Within comparative psychology, the evolution of animal cognition is typically studied either by comparing indirect measures of cognitive abilities (e.g., relative brain size) across many species or by conducting batteries of decision-making experiments among (typically) a few captive species.

A Comparative Perspective on Three Primate Species' Responses to a Pictorial Emotional Stroop Task.

The Stroop effect describes interference in cognitive processing due to competing cognitive demands. Presenting emotionally laden stimuli creates similar Stroop-like effects that result from participants' attention being drawn to distractor stimuli. Here, we adapted the methods of a pictorial Stroop study for use with chimpanzees (N = 6), gorillas (N = 7), and Japanese macaques (N = 6).

Chimpanzee Coordination and Potential Communication in a Two-touchscreen Turn-taking Game.

Recent years have seen a growing interest in the question of whether and how groups of nonhuman primates coordinate their behaviors for mutual benefit. On the one hand, it has been shown that chimpanzees in the wild and in captivity can solve various coordination problems. On the other hand, evidence of communication in the context of coordination problems is scarce.

Sound symbolic congruency detection in humans but not in great apes.

Theories on the evolution of language highlight iconicity as one of the unique features of human language. One important manifestation of iconicity is sound symbolism, the intrinsic relationship between meaningless speech sounds and visual shapes, as exemplified by the famous correspondences between the pseudowords 'maluma' vs. 'takete' and abstract curved and angular shapes.

The word order of languages predicts native speakers' working memory.

The relationship between language and thought is controversial. One hypothesis is that language fosters habits of processing information that are retained even in non-linguistic domains. In left-branching (LB) languages, modifiers usually precede the head, and real-time sentence comprehension may more heavily rely on retaining initial information in working memory.

Food cleaning in gorillas: Social learning is a possibility but not a necessity.

Food cleaning is widespread in the animal kingdom, and a recent report confirmed that (amongst other behaviours) wild western lowland gorillas also show food cleaning. The authors of this report conclude that this behaviour, based on its distribution patterns, constitutes a potential candidate for culture. While different conceptualisations of culture exist, some more and some less reliant on behavioural form copying, all of them assign a special role to social learning processes in explaining potentially cultural behaviours.

Information seeking about tool properties in great apes.

Evidence suggests that great apes engage in metacognitive information seeking for food items. To support the claim that a domain-general cognitive process underlies ape metacognition one needs to show that selective information seeking extends to non-food items. In this study, chimpanzees (Pan troglodytes) and orangutans (Pongo abelii) either had to determine the location of a desired food item or a property of a non-food item (length of a tool).

How chimpanzees (Pan troglodytes) perform in a modified emotional Stroop task.

The emotional Stroop task is an experimental paradigm developed to study the relationship between emotion and cognition. Human participants required to identify the color of words typically respond more slowly to negative than to neutral words (emotional Stroop effect). Here we investigated whether chimpanzees (Pan troglodytes) would show a comparable effect.

Cross-cultural evidence of value structures and priorities in childhood.

We broaden the developmental focus of the theory of universals in basic human values (Schwartz, 1992, Advances in Experimental Social Psychology) by presenting supportive evidence on children's values from six countries: Germany, Italy, Poland, Bulgaria, the United States, and New Zealand. 3,088 7-11-year-old children completed the Picture-Based Value Survey for Children (PBVS-C, Döring et al., 2010, J.

Food washing and placer mining in captive great apes.

Sweet potato washing and wheat placer mining in Japanese macaques (Macaca fuscata) are among the most well known examples of local traditions in non-human animals. The functions of these behaviors and the mechanisms of acquisition and spread of these behaviors have been debated frequently. Prompted by animal caretaker reports that great apes [chimpanzees (Pan troglodytes), bonobos (Pan paniscus), gorillas (Gorilla gorilla), and orangutans (Pongo abelii)] at Leipzig Zoo occasionally wash their food, we conducted a study of food washing behaviors that consisted of two parts.