An important extension to our understanding of evolutionary processes has been the discovery of the roles that individual and social learning play in creating recurring phenotypes on which selection can act. Cultural change occurs chiefly through invention of new behavioral variants combined with social transmission of the novel behaviors to new practitioners. Therefore, understanding what makes some individuals more likely to innovate and/or transmit new behaviors is critical for creating realistic models of culture change. The difficulty in identifying what behaviors qualify as new in wild animal populations has inhibited researchers from understanding the characteristics of behavioral innovations and innovators. Here, we present the findings of a long-term, systematic study of innovation (10 y, 10 groups, and 234 individuals) in wild capuchin monkeys (Cebus capucinus) in Lomas Barbudal, Costa Rica. Our methodology explicitly seeks novel behaviors, requiring their absence during the first 5 y of the study to qualify as novel in the second 5 y of the study. Only about 20% of 187 innovations identified were retained in innovators' individual behavioral repertoires, and 22% were subsequently seen in other group members. Older, more social monkeys were more likely to invent new forms of social interaction, whereas younger monkeys were more likely to innovate in other behavioral domains (foraging, investigative, and self-directed behaviors). Sex and rank had little effect on innovative tendencies. Relative to apes, capuchins devote more of their innovations repertoire to investigative behaviors and social bonding behaviors and less to foraging and comfort behaviors.innovation | Cebus capucinus | cultural evolution | phenotypic plasticity | learning B ehavioral innovation has long been a topic of interest for researchers dedicated to studying the evolution of culture, because it is a driver of cultural change (1, 2). The types of behavioral traditions that are of greatest interest to evolutionary modelers are those starting with an innovation that then spreads via social learning. Understanding the characteristics of (i) behavioral innovations (which are roughly analogous to genetic mutations) and (ii) the individuals who invent these behaviors is critical to understanding cultural evolution and its relationship to genetic evolution. Innovation is also of interest to evolutionary biologists who study the role that learning plays in macroevolution, because it is a type of phenotypic plasticity that can affect the direction of natural selection (3). Ability to innovate can enhance reproductive success (for example, by enabling individuals to exploit new resources) (4-6). Innovation can generate the Baldwin effect, in which learned traits create recurring phenotypes that select for morphological adaptations, eventually leading to speciation (3, 7). Innovation is also of interest as a correlate of intelligence more generally, and the ability to solve novel cognitive problems presented by experimenters can be positively ...