Many studies in both free-ranging and captive apes have shown that some forms of laterality of hand function occur in non-human primates¹. However, true handedness (sensu McGrew and Marchant²), when most individuals show a skew in hand preference in the same direction across different tasks, seems to be restricted to humans. Other hominoids appear unlateralized in simpler tasks, such as reaching, picking up objects, and grooming³, but they show hand preference for more complex tasks, such as tool-using^{2, 4, 5} or elaborate food processing^{6, 7}.

Laterality in termite-fishing⁸ has been studied only at Gombe, and the two published data-sets are congruent. McGrew and Marchant^{2, 9} reported that most (27 of 36) chimpanzees showed an individualized hand preference for right or left, as did Lonsdorf and Hopkins10 (16 of 17) for termite-fishing in the same community. No other data have been published for chimpanzee communities elsewhere. This study asks if termite-fishing by Fongoli chimpanzees is lateralized, shows hand preference (individuals are lateralized, but with no populational preference for either hand), or task specialization (all or most individuals use the same hand).