Gc. Westergaard et Sj. Suomi, HIERARCHICAL COMPLEXITY OF COMBINATORIAL MANIPULATION IN CAPUCHIN MONKEYS (CEBUS-APELLA), American journal of primatology, 32(3), 1994, pp. 171-176
The purpose of this study was to examine the hierarchical complexity o
f combinatorial manipulation in capuchin monkeys (Cebus apella). Two e
xperiments were conducted. In Experiment 1 capuchins were presented wi
th an apparatus designed to accommodate the use of probing tools. In E
xperiment 2 the same capuchins were presented with sets of nesting con
tainers. Five of the ten subjects used probing tools and seven subject
s placed objects in the containers. The capuchins' behavior reflected
three hierarchically organized combinatorial patterns displayed by chi
mpanzees and human infants. Although the capuchins sometimes displayed
the two more complex patterns (''pot'' and ''subassembly''), their co
mbinatorial behavior was dominated by the simplest pattern (''pairing'
'). In this regard capuchins may not attain the same grammar of manipu
lative action that has been reported for chimpanzees and young human c
hildren. (C) 1994 Wiley-Liss, Inc.