ABSTRACT
C Omparisons Of Nonhuman Primates have traditionally contrasted the behavior patterns of New World and Old World monkeys. The Platyrrhines of the New World are said to live in loosely organized social groups in which individuals are rarely aggressive and dominance behavior almost absent. The social group of the Old World Catarrhines is described as more rigidly organized by social hierarchies, based on dominance-oriented behavior and frequent fighting among adult males. To the extent that this distinction is valid, the behavioral differences being compared are not those between New and Old World monkeys, but between arboreal and terrestrial species. The only systematic field studies of New World monkeys have been on the howler monkey, Alouatta palliata (Carpenter, 1934; Collias and Southwick, 1952; Altmann, 1959), and Carpenter's (1935) brief observations on spider monkeys, Ateles geoffroyi. Both of these species are highly specialized, morphologically and behaviorally, for living in the tall trees of the South American jungle. They are seldom seen in the lower branches of trees and almost never come to the ground. On the other hand, behavioral studies of Old World monkeys, principally those of Zuckerman (1932) and Carpenter (1942), had until recently included only species in the baboon-macaque group. In both morphology and behavior the baboon-macaques are more terrestrially adapted than any other monkey or ape.
