Metacognition in nonhuman primates: a review of current knowledge

Abstract

Metacognition, the ability to monitor and control one's own cognitive processes, has long been considered a hallmark of human cognition. However, two decades of research have provided compelling evidence of metacognitive-like abilities in some nonhuman primates. This review synthesizes current knowledge on the subject, highlighting key experimental paradigms and empirical findings, with an emphasis on the latest studies. Thanks to advances in methods and efforts to counter alternative explanations, there is now a consensus that great apes and some macaque species can monitor and control some of their cognitive processes. Despite numerous investigations, however, whether capuchin monkeys are metacognitive remains unclear. Critical gaps persist in our understanding of metacognition across species. We discuss the importance of expanding research to include a wider range of primate species and the potential role of ecological factors in shaping metacognitive capacities. In addition, we consider some promising avenues for future research, including neurophysiological approaches, studies of metacognitive errors, and field experiments.

Keywords: Literature review; Metacognition; Nonhuman primates; Phylogenetic comparison.

Fig. 1

Basic tubes test setup (E experimenter, S subject) as first introduced by Call and Carpenter (2001)

Fig. 2

Schematic of the apparatus used by O’Madagain et al. (2022) to test belief revision. On the “first view”, one reward looks bigger than the other. On the “second view”, the boxes have been rotated and the opposite reward appears bigger (in the “conflicting” condition)

Fig. 3

Simplified schematic of protocol using a betting paradigm to test retrospective (a) and prospective (b) judgment in monkeys. The white band with yellow circles on the right edge represents a token bank that can be filled and emptied depending on the subject’s accuracy on the test and betting choice. When the bank is full, the subject earns a food reward

Fig. 4

Free-ranging Japanese macaques tested on the tubes task at the Awajishima monkey center (Subias et al. 2024a). Two testing locations were set up, with the experimenter standing inside wire-mesh huts. The white boxes were used to adjust the apparatus height and to manipulate the effort required to look