Divergence in bonobo and chimpanzee social life.

New research is shedding light on the nuances and complexity of social relationships in our closest relatives, revealing cooperative intergroup relationships in bonobos, in contrast to lethal intergroup violence in chimpanzees. At the same time, intragroup relationships, at least among males, are characterized by higher frequencies of aggression and lower rates of coalitionary cooperation in bonobos than chimpanzees.

In search of animal normativity: a framework for studying social norms in non-human animals.

Social norms - rules governing which behaviours are deemed appropriate or inappropriate within a given community - are typically taken to be uniquely human. Recently, this position has been challenged by a number of philosophers, cognitive scientists, and ethologists, who have suggested that social norms may also be found in certain non-human animal communities. Such claims have elicited considerable scepticism from norm cognition researchers, who doubt that any non-human animals possess the psychological capacities necessary for normative cognition.

Bonobos and chimpanzees remember familiar conspecifics for decades.

Recognition and memory of familiar conspecifics provides the foundation for complex sociality and is vital to navigating an unpredictable social world [Tibbetts and Dale, , 529-537 (2007)]. Human social memory incorporates content about interactions and relationships and can last for decades [Sherry and Schacter, , 439-454 (1987)]. Long-term social memory likely played a key role throughout human evolution, as our ancestors increasingly built relationships that operated across distant space and time [Malone .

Eye-tracking as a window into primate social cognition.

Over the past decade, noninvasive, restraint-free eye-tracking research with primates has transformed our understanding of primate social cognition. The use of this technology with many primate species allows for the exploration and comparison of how these species attend to and understand social agents and interactions. The ability to compare and contrast the cognitive capacities of various primate species, including humans, provides insight into the evolutionary mechanisms and selective pressures that have likely shaped social cognition in similar and divergent ways across the primate order.

Representing knowledge, belief, and everything in between: Representational complexity in humans and other apes.

Building on Phillips and colleagues' case for the primacy of knowledge, we advocate for attention to diversity in mentalizing constructs within, as well as between, knowledge and belief. Ultimately, as great apes and other animals show, the development and evolution of theory of mind may reflect a much greater range of incremental elaborations of representational or computational complexity.

Little evidence that Eurasian jays protect their caches by responding to cues about a conspecific's desire and visual perspective.

Eurasian jays have been reported to protect their caches by responding to cues about either the visual perspective or current desire of an observing conspecific, similarly to other corvids. Here, we used established paradigms to test whether these birds can - like humans - integrate multiple cues about different mental states and perform an optimal response accordingly. Across five experiments, which also include replications of previous work, we found little evidence that our jays adjusted their caching behaviour in line with the visual perspective and current desire of another agent, neither by integrating these social cues nor by responding to only one type of cue independently.

Social bonds provide multiple pathways to reproductive success in wild male chimpanzees.

In most male mammals, fitness is strongly shaped by competitive access to mates, a non-shareable resource. How, then, did selection favor the evolution of cooperative social bonds? We used behavioral and genetic data on wild chimpanzees () in Gombe National Park, Tanzania, to study the mechanisms by which male-male social bonds increase reproductive success. Social bonds increased fitness in several ways: first, subordinate males that formed strong bonds with the alpha male had higher siring success.

Erratum to "Bonobos and chimpanzees preferentially attend to familiar members of the dominant sex" [ 177 (2021) 193-206].

[This corrects the article DOI: 10.1016/j.anbehav.

The application of noninvasive, restraint-free eye-tracking methods for use with nonhuman primates.

Over the past 50 years there has been a strong interest in applying eye-tracking techniques to study a myriad of questions related to human and nonhuman primate psychological processes. Eye movements and fixations can provide qualitative and quantitative insights into cognitive processes of nonverbal populations such as nonhuman primates, clarifying the evolutionary, physiological, and representational underpinnings of human cognition. While early attempts at nonhuman primate eye tracking were relatively crude, later, more sophisticated and sensitive techniques required invasive protocols and the use of restraint.

Implicit Measures Help Demonstrate the Value of Conservation Education in the Democratic Republic of the Congo.

Biodiversity is being lost at unprecedented rates. Limited conservation resources must be prioritized strategically to maximize impact. Here we introduce novel methods to assess a small-scale conservation education program in the Democratic Republic of Congo.

Great apes use self-experience to anticipate an agent's action in a false-belief test.

Human social life depends on theory of mind, the ability to attribute mental states to oneself and others. A signature of theory of mind, false belief understanding, requires representing others' views of the world, even when they conflict with one's own. After decades of research, it remains controversial whether any nonhuman species possess a theory of mind.

Theory of mind in animals: Current and future directions.

Theory of mind (ToM; a.k.a.

Bonobos voluntarily hand food to others but not toys or tools.

A key feature of human prosociality is , the most active form of sharing in which donors voluntarily hand over resources Direct transfers buffer hunter-gatherers against foraging shortfalls. The emergence and elaboration of this behaviour thus likely played a key role in human evolution by promoting cooperative interdependence and ensuring that humans' growing energetic needs (e.g.

Human ostensive signals do not enhance gaze following in chimpanzees, but do enhance object-oriented attention.

The previous studies have shown that human infants and domestic dogs follow the gaze of a human agent only when the agent has addressed them ostensively-e.g., by making eye contact, or calling their name.

Bonobos Prefer Individuals that Hinder Others over Those that Help.

Humans closely monitor others' cooperative relationships [1, 2]. Children and adults willingly incur costs to reward helpers and punish non-helpers-even as bystanders [3-5]. Already by 3 months, infants favor individuals that they observe helping others [6-8].

A test of the submentalizing hypothesis: Apes' performance in a false belief task inanimate control.

Much debate concerns whether any nonhuman animals share with humans the ability to infer others' mental states, such as desires and beliefs. In a recent eye-tracking false-belief task, we showed that great apes correctly anticipated that a human actor would search for a goal object where he had last seen it, even though the apes themselves knew that it was no longer there. In response, Heyes proposed that apes' looking behavior was guided not by social cognitive mechanisms but rather domain-general cueing effects, and suggested the use of inanimate controls to test this alternative submentalizing hypothesis.

Eye tracking uncovered great apes' ability to anticipate that other individuals will act according to false beliefs.

Using a novel eye-tracking test, we recently showed that great apes anticipate that other individuals will act according to false beliefs. This finding suggests that, like humans, great apes understand others' false beliefs, at least in an implicit way. One key question raised by our study is why apes have passed our tests but not previous ones.

Great apes anticipate that other individuals will act according to false beliefs.

Humans operate with a "theory of mind" with which they are able to understand that others' actions are driven not by reality but by beliefs about reality, even when those beliefs are false. Although great apes share with humans many social-cognitive skills, they have repeatedly failed experimental tests of such false-belief understanding. We use an anticipatory looking test (originally developed for human infants) to show that three species of great apes reliably look in anticipation of an agent acting on a location where he falsely believes an object to be, even though the apes themselves know that the object is no longer there.

No evidence for contagious yawning in lemurs.

Among some haplorhine primates, including humans, relaxed yawns spread contagiously. Such contagious yawning has been linked to social bonds and empathy in some species. However, no studies have investigated contagious yawning in strepsirhines.

Social bonds in the dispersing sex: partner preferences among adult female chimpanzees.

In most primate societies, strong and enduring social bonds form preferentially among kin, who benefit from cooperation through direct and indirect fitness gains. Chimpanzees, , differ from most species by showing consistent female-biased dispersal and strict male philopatry. In most East African populations, females tend to forage alone in small core areas and were long thought to have weak social bonds of little biological significance.

Bonobos and chimpanzees exhibit human-like framing effects.

Humans exhibit framing effects when making choices, appraising decisions involving losses differently from those involving gains. To directly test for the evolutionary origin of this bias, we examined decision-making in humans' closest living relatives: bonobos (Pan paniscus) and chimpanzees (Pan troglodytes). We presented the largest sample of non-humans to date (n = 40) with a simple task requiring minimal experience.