harnad@mind.UUCP (Stevan Harnad) (08/04/88)
Below is the abstract of a forthcoming target article to appear in Behavioral and Brain Sciences (BBS), an international journal of "open peer commentary" in the biobehavioral and cognitive sciences, published by Cambridge University Press. For information on how to serve as a commentator or to nominate qualified professionals in these fields as commentators, please send email to: harnad@mind.princeton.edu or write to: BBS, 20 Nassau Street, #240, Princeton NJ 08542 [tel: 609-921-7771] Spontaneous tool use and sensorimotor intelligence in Cebus and other monkeys and apes Suzanne Chevalier Skolnikoff Human Interaction Laboratory Department of Psychiatry University of California, San Fransisco Spontaneous tool use and sensorimotor intelligence in Cebus were observed to determine whether tool use is discovered fortuitously and learned by trial and error or, rather, advanced sensorimotor abilities (experimentation and insight) are critical in its development and evolution. During 62 hours of observing captive groups of cebus monkeys (a total of 12 animals), 38 series and 66 acts of spontaneous tool use were recorded. Nine monkeys (75%) used tools; 14 kinds of tool use were observed. Of seven captive spider monkeys observed for 21 hours, none used tools. Comparative observations of sensorimotor intelligence were made using Piaget's model. The sensorimotor basis of tool use was also analyzed. Cebus showed all six of Piaget's levels of sensorimotor intelligence, whereas spider monkeys showed only the first four stages. Besides these correlations between tool use and advanced sensorimotor ability, 37 of the 38 tool-use series and 65 of the 66 individual acts involved Stage 5 and 6 sensorimotor mechanisms in Cebus; only one series involved Stage 3 fortuitous discovery and Stage 4 coordinations. This study and a literature survey suggest that high tool-using propensity among primates is based on advanced sensorimotor ability rather than fortuitous discovery. -- Stevan Harnad ARPANET: harnad@mind.princeton.edu harnad@princeton.edu harnad@confidence.princeton.edu srh@flash.bellcore.com harnad@mind.uucp BITNET: harnad%mind.princeton.edu@pucc.bitnet UUCP: princeton!mind!harnad CSNET: harnad%mind.princeton.edu@relay.cs.net