Chimpanzee handedness revisited: 55 years since Finch (1941).

Chimpanzees and other great apes have long held the fascination of psychologists because of their morphological and behavioral similarities to humans. This paper describes the historical interest in studies on chimpanzee handedness and reviews current findings. Data are presented which suggest that transient changes in posture result in the transient expression of right-handedness in chimpanzees. The role of tool use as an evolutionary mechanism underlying the expression of right-handedness is challenged. Rather, emphasis is placed on the role of bimanual feeding as a behavioral adaptation for the expression of handedness. Suggestions for further research on the nature of nonhuman primate handedness are made in light of these findings.