Comparative studies of squirrel monkeys (Saimiri sciureus) and titi monkeys (Callicebus moloch): performance on...

Squirrel monkeys (Saimiri sciureus) and titi monkeys (Callicebus moloch) were studied in tasks involving reaching for food in near space (arm's reach). Although performance by monkeys of the two species differed in several ways familiar from previous studies, the species did not differ in the tendency to adopt a habitual position or limb during reaching. The findings contrast with previous work on spatial preferences in these species in tasks involving movement of the whole body. Together with the results of previous studies on movement patterns in these two species, the findings are placed in a comparative psychological framework of the proximate sources of use of space in nature.