Abstract.
This paper explores the effectiveness of token rewards in maintaining chimpanzees (Pan troglodytes) in working at intellectually costly tasks, and studies the "saving" behavior of the subjects, investigating the factors that can condition it. Two experiments were run. Tokens were introduced as rewards in a matching-to-sample task and used as exchange tools for food by three adult female chimpanzees. Subjects’ performances were maintained at constant high levels of accuracy, suggesting that the tokens were almost equivalent to direct food rewards. The results also showed the emergence of saving behavior. The subjects spontaneously saved the tokens during the matching-to-sample task before exchanging them for food. The chimpanzees also learned a new symbolic discrimination task, with tokens as the reward. During this learning process a rarely reported phenomenon emerged: one of the subjects showed symmetry, a form of stimulus equivalence.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Accepted after revision: 7 August 2001
Electronic Publication
Rights and permissions
About this article
Cite this article
Sousa, C., Matsuzawa, T. The use of tokens as rewards and tools by chimpanzees (Pan troglodytes). Anim.Cogn. 4, 213–221 (2001). https://doi.org/10.1007/s100710100104
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s100710100104