Can chimpanzees (Pan troglodytes) discriminate appearance from reality?

  title={Can chimpanzees (Pan troglodytes) discriminate appearance from reality?},
  author={Carla Krachun and Josep Call and Michael Tomasello},

Figures and Tables from this paper

All great ape species (Gorilla gorilla, Pan paniscus, Pan troglodytes, Pongo abelii) and two-and-a-half-year-old children (Homo sapiens) discriminate appearance from reality.
All great ape species and children successfully identified the bigger stick, despite its smaller appearance, in the experimental conditions, but not in the control.
Intuitive optics: what great apes infer from mirrors and shadows
Findings suggest that apes are sensitive to the optical relation between mirror images and shadows and their physical referents.
Pushmi-pullyu Representations and Mindreading in Chimpanzees
Lurz and Krachun (2011) propose a new experimental protocol designed to discriminate genuine mindreading animals from mere behavior-readers and to give evidence in favor of the claim that chimpanzees
A New Change-of-Contents False Belief Test: Children and Chimpanzees Compared
In the handful of existing comparative false belief studies, chimpanzees have consistently failed tests that 5- to 6-year-old children have passed. However, those tests were either explicitly
What Apes Know about Seeing
What constitutes evidence for level 1 visual perspective taking (hereafter, VPT1) in nonhuman primates is examined and it is argued that the critics’ position is misguided.
How Could We Know Whether Nonhuman Primates Understand Others’ Internal Goals and Intentions? Solving Povinelli’s Problem
A persistent methodological problem in primate social cognition research has been how to determine experimentally whether primates represent the internal goals of other agents or just the external
The Primate Origins of Human Social Cognition
It is argued that this evolutionary perspective can help adjudicate between different proposals on the link between human-specific forms of social cognition and language, and then examine the evidence for apparently human-unique aspects of theory of mind that may be linked to language.


Chimpanzees (Pan troglodytes) know what can be seen from where
It is suggested that chimpanzees have good visual perspective taking abilities with regard to themselves as well as others, and that both likely reflect a more general knowledge, at least implicit, of what can be seen from where.
Chimpanzees know what conspecifics do and do not see
It is suggested that chimpanzees know what conspecifics can and cannot see, and, furthermore, that they use this knowledge to devise effective social-cognitive strategies in naturally occurring food competition situations.
"Conservations" with a chimpanzee.
  • S. Muncer
  • Psychology, Biology
    Developmental psychobiology
  • 1983
Two chimpanzees (Pan tryglodytes), Fanny and Jane, were presented with liquid and number conservation problems. One chimpanzee, Jane, was successful in solving both sets of problems in that she was
A competitive nonverbal false belief task for children and apes.
Children displayed an understanding of the competitor's false belief by correctly choosing the other container to find the reward and apes looked more often at the unchosen container in false belief trials than in true belief control trials, possibly indicating some implicit or uncertain understanding that needs to be investigated further.
Do apes and children know what they have seen?
Abstract. Chimpanzees and young children understand much about what other individuals have and have not seen. This study investigates what they understand about their own visual perception.
Responses to quantity: perceptual versus cognitive mechanisms in chimpanzees (Pan troglodytes).
  • S. Boysen, G. Berntson
  • Psychology, Biology
    Journal of experimental psychology. Animal behavior processes
  • 1995
It is suggested that a basic predisposition to respond to the perceptual-motivational features of incentive stimuli can interfere with task performance and that this interference can be overridden when abstract symbols serve as choice stimuli.
Do chimpanzees know what conspecifics know?
Chimpanzees know what conspecifics have and have not seen (do and do not know), and that they use this information to devise effective social-cognitive strategies.
Chimpanzees really know what others can see in a competitive situation
It is shown that in some food competition contexts, subordinate chimpanzees do take the visual perspective of dominant individuals, preferentially targeting a hidden piece of the food that the dominant cannot see over a piece that is visible to both individuals.
How the great apes (Pan troglodytes, Pongo pygmaeus, Pan paniscus, and Gorilla gorilla) perform on the reversed contingency task: the effects of food quantity and food visibility.
The authors compared the performance of 4 great ape species on the reversed contingency task while manipulating food quantity and food visibility and showed no systematic species differences but large individual differences.
Size matters: impact of item size and quantity on array choice by chimpanzees (Pan troglodytes).
Findings replicate previous findings showing chimpanzees' difficulties with quantity judgments under reverse reward contingencies and also show that individual item size exerts a more powerful interference effect.