The form of the unworn male Cercopithecoid maxillary canine tooth (C') is effectively adapted for stabbing and slashing. Its essential features are maintained by wear against the mandibular canine (C1) and first premolar (P3) teeth. The cusp tip of C1 is sharpened by reciprocal wear against C'. The distribution of apposing wear facets indicates that functional attrition results from honing activity largely distinct from mastication. Functional attrition also occurs in reduced form in females and is produced within the masticatory excursive range. The significance of the “sectorial” form of P3 is analyzed. Its elongated mesiobuccal surface serves the dual purpose of honing the distal cutting edge of C' and functioning as a cutting block against which vegetation is stabilized and shredded by the cervical third of the distal cutting edge of C'. Behavioral aspects of honing are correlated with field observations linking tooth grinding with aggression, tension release, and communication. Parallel human behavior is cited and the suggestion is made that human tooth grinding with its highly charged emotional overtones is largely relict behavior that once had high survival value in a canine tooth honing context.