International Journal of Primalology, Vol. 20, No. 6, 1999 Hand Preferences for a Haptic Task in Chimpanzees (Pan troglodytes) Agnes Lacreuse,1,5 Lisa A. Parr,2,3 Hope M. Smith,3 and William D. Hopkins3,4 Received December 7, 1998; revised April 12, 1999; accepted June 14, 1999 We tested the hand preferences of 20 chimpanzees (Pan troglodytes) for a haptic task requiring individuals to search for grapes in an opaque bucket filled with water. We compared these data to the hand preferences displayed by the same chimpanzees during reaching and bimanual feeding tasks. The chimpanzees displayed no significant hand preference for the reaching or bimanual feeding tasks, but exhibited a right-hand preference while per- forming the haptic task. In contrast, New and Old World monkeys display left-hand preferences for similar tasks. We discuss the relevance of these findings for the evolution of handedness in primates. A growing number of studies have documented the presence of neuro- anatomical (Bradshaw and Rogers, 1993; Gannon et al, 1998; Hopkins et al., 1998), functional (Bradshaw and Rogers, 1993), and motor asymmetries in nonhuman primates (Bradshawand Rogers, 1993; Fagot and Vauclair,1991; Fagot et al, 1997b; MacNeilage et al., 1987; Ward and Hopkins, 1993). 1Division of Neuroscience, Yerkes Regional Primate Research Center, Emory University, Atlanta, Georgia 30322. 2Department of Psychology, Emory University, Atlanta, Georgia 30329. 3Living Links Center, Emory University, Atlanta, Georgia 30322. • • Departmen t of Psychology, Berry College, Mt. Berry, Georgia 30149. 5Correspondence should be addressed to Dr. A. Lacreuse, Division of Neuroscience, Yerkes Regional Primate Research Center, Emory University, Atlanta, Georgia 30322; e-mail: alacreu@rmy.emory.edu. KEY WORDS: haptic; laterality; handedness; chimpanzee. 867 0164.0291/99/1200-0867S16.00/0 © 1999 Plenum Publishing Corporation