Gaze alternation during “pointing” by squirrel monkeys (Saimiri sciureus)?
Gaze alternation (GA) is considered a hallmark of pointing in human infants, a sign of intentionality underlying the gesture. GA has occasionally been observed in great apes, and reported only anecdotally in a few monkeys. Three squirrel monkeys that had previously learned to reach toward out-of-reach food in the presence of a human partner were videotaped while the latter visually attended to the food, a distractor object, or the ceiling. Frame-by-frame video analysis revealed that, especially when reaching toward the food, the monkeys rapidly and repeatedly switched between looking at the partner’s face and the food. This type of GA suggests that the monkeys were communicating with the partner. However, the monkeys’ behavior was not influenced by changes in the partner’s focus of attention.
KeywordsGaze alternation Squirrel monkeys Pointing Attention Communication
This study was supported by JSPS Grants-in-Aid for Scientific Research Nos. 13410026 and 17300085 to KF and 21st Century COE Program, D-10 to Kyoto University, and by awards from the Carnegie Trust for the Universities of Scotland and the Great Britain Sasakawa Foundation to JRA. The assistance of Hika Kuroshima with analyses and illustrations is gratefully acknowledged.
- Bates E, Camaioni L, Volterra V (1975) The acquisition of preformatives prior to speech. Merrill-Palmer Quart 21:205–226Google Scholar
- Gomez J-C (1996) Ostensive behavior in great apes: the role of eye contact. In: Russon AE, Bard KA, Parker ST (eds) Reaching into thought: the minds of the great apes. Cambridge University Press, Cambridge, pp 131–151Google Scholar
- Kumashiro M, Ishibashi H, Itakura S, Iriki A (2002) Bidirectional communication between a Japanese monkey and a human through eye gaze and pointing. Curr Psychol Cogn 21:3–32Google Scholar