Virtually capable : investigating chimpanzees' cognitive abilities in competition and hunting using virtual environments

Chimpanzees’ way of life places strong demands on their cognitive abilities. But debate has long existed over whether their cognition is in any way mentalistic—based on high-level processes, comparable to that of humans—or whether their behaviour is more parsimoniously explained by lower-level processes. This portfolio comprises four papers in which I leveraged Virtual Environments as an experimental paradigm to explore this question with respect to two specific aspects of chimpanzee cognition. First, their hunting strategies—particularly the extent to which they attempt to predict their prey’s behaviour. Second, their social strategies—particularly how far they view their competitors as agents and consider their minds. In the first paper presented here, I challenged chimpanzees with navigating a three-dimensional Virtual Environment, avoiding obstacles, and capturing moving virtual prey. They learned to do so rapidly, succeeding at far higher rates than when the environment was instead shown from a two-dimensional, top-down viewpoint. In the second paper, I tasked chimpanzees with capturing a fast-moving virtual prey that could not be caught by chasing. Two subjects learned to intercept the prey by anticipating its trajectory, and this ability proved robust and flexible across follow-up tasks. In my third study, I failed to find evidence that chimpanzees could attribute preferences to competitors. When challenged with approaching the correct virtual prey depending on which of two virtual competitors was present, they chose randomly, or according to side biases. Finally, I examined chimpanzees’ attribution of agency to novel virtual competitors, which either resembled animals or simple geometric shapes. I found evidence that, similarly to human infants, chimpanzees use animal features to distinguish agents from mere physical objects, and do not rely on self-propulsion cues. Together, my results contribute towards the perspective that chimpanzees are capable of sophisticated cognition, but also make use of simpler strategies; and that apparently intelligent behaviour that appears reminiscent of our own is not necessarily underpinned by the same mental processes. I conclude by adding my voice to those calling for increased sensitivity to ecological and motivational validity in the designing of cognition experiments so as to better ensure that negative or positive results are truly reflective of chimpanzees’ minds.