Understanding visual access in common marmosets, Callithrix jacchus: perspective taking or behaviour reading?

We tested common marmosets’ understanding of visual access in a series of experiments. In experiment 1, we investigated whether marmosets know what conspecifics do and do not see, using a food competition paradigm originally developed for chimpanzees, Pan troglodytes. Subordinate marmosets consistently chose a piece of food only visible to them and not one that […]

Visual attention and its relation to knowledge states in chimpanzees, Pan troglodytes

Primates rely on visual attention to gather knowledge about their environment. The ability to recognize such knowledge-acquisition activity in another may demonstrate one aspect of Theory of Mind. Using a series of experiments in which chimpanzees were presented with a choice between an experimenter whose visual attention was available and another whose vision was occluded, […]

The performance of bonobos (Pan paniscus), chimpanzees (Pan troglodytes), and orangutans (Pongo pygmaeus) in two versions of an object-choice task

The object-choice task tests animals’ ability to use human-given cues to find a hidden reward located in 1 of 2 (or more) containers. Great apes are generally unskillful in this task whereas other species including dogs (Canis familiaris) and goats (Capra hircus) can use human-given cues to locate the reward. However, great apes are typically […]

Does early care affect joint attention in great apes (Pan troglodytes, Pan paniscus, Pongo abelii, Pongo pygmaeus, Gorilla gorilla)?

The ability to share attention with another is the foundation on which other theory of mind skills are formed. The quality of care received during infancy has been correlated with increased joint attention in humans. The purpose of this study was to assess the effects of care style (responsive or basic) and caregiver type (ape […]

All great ape species follow gaze to distant locations and around barriers

Following the gaze direction of conspecifics is an adaptive skill that enables individuals to obtain useful information about the location of food, predators, and group mates. In the current study, the authors compared the gaze-following skills of all 4 great ape species. In the 1st experiment, a human either looked to the ceiling or looked […]

Bonobos and chimpanzees infer the target of another’s attention

We examined the ability of bonobos, Pan paniscus (N ¼ 39), and chimpanzees, Pan troglodytes (N ¼ 74), to infer the target of an experimenter’s visual attention in a series of three experiments. In each experiment subjects were first introduced to a novel object while an experimenter’s (E1) visual access to this object was manipulated […]

Friendship affects gaze following in a tolerant species of macaque, Macaca nigra

Gaze following, the ability to follow the direction in which others are looking, is thought to allow individuals to acquire valuable information from their physical and social environment. Recent studies, using artificial stimuli, showed that gaze following can be modulated by social factors such as dominance or social context, suggesting the importance of integrating these […]

Do rhesus macaques, Macaca mulatta, understand what others know when gaze following?

A basic tendency to look where others are looking provides animals with the opportunity to learn about important objects in the environment, such as the location of conspecifics, food and predators. Although research has shown that many social species are able to follow others’ gaze, the extent to which different species rely on sophisticated cognitive […]