Available online at www.sciencedirect.com Robust capuchin tool use cognition in the wild Tiago Falótico 1,2, * Most of the studies on primate cognition focus on Catarrhines primates closely related to humans. One alternative primate model for understanding primate cognition is the Platyrrhine capuchin monkey (genus Cebus and Sapajus), which has several convergent traits to hominins. Although capuchins have been targets of cognition studies in laboratories for decades, primates in captivity lack the complete social structures and ecological factors associated with free-ranging environments. Increasing the focus to wild capuchins represents a welcome change to complement captive primate cognition studies in the past decades. Here I do a non-exhaustive review of cognition research on wild robust capuchins (Sapajus), focusing on tool use. Those studies are on the rise and are a source of valuable information to understand primate cognition in natural, evolutionary valid environments, where cognition can be tested and studied in situations similar to those in which those traits evolved. Addresses 1 School of Arts, Sciences and Humanities, University of São Paulo, Brazil 2 Neotropical Primates Research Group, Brazil Corresponding author: Tiago Falótico (tfalotico@gmail.com) * Twitter account: @tfalotico Current Opinion in Behavioral Sciences 2022, 46:101170 This review comes from a themed issue on Cognition in the Wild Edited by Alexandra Rosati, Zarin Machanda and Katie Slocombe https://doi.org/10.1016/j.cobeha.2022.101170 2352-1546/© 2022 Elsevier Ltd. All rights reserved. Introduction Nonhuman primates have been one of the main targets of cognition studies due to their evolutionary proximity to humans. Most of those studies focus on species most closely related to humans, such as apes and Afro- Eurasian Monkeys [1]. However, the capuchin monkey (genus Cebus and Sapajus) is an interesting primate model to understand primate cognition. Those American primates are separated by approximately 32–43 Ma from the human lineage [2,3] but present several character- istics — tool use, high encephalization, hand mor- phology, dietary fexibility [4] — that are like hominoids, making them an excellent alternative model to study key cognition traits shared with humans and other apes. Capuchin monkeys have been targeted for cognition studies in laboratory settings for as long as primatology has been a discipline [4]. Easily accessible to researchers and allowing the control of certain variables which cannot be as easily controlled in the wild (e.g. diet, op- portunities to engage in tasks, time of exposure), ca- puchin monkeys have been studied to examine several traits of cognition: physical causality [5–7], tool use [8–13], social reasoning [14–16], learning [17,18], among other topics. Although valuable data can be gathered from captivity, sometimes with the same results as in the wild or com- plementing those [19,20], primates in captive studies usually lack the complete social structures associated with wild or free-ranging environments. Moreover, they often do not interact with ecological factors wild in- dividuals evolved with, making the ecological validity of some of those captive studies more limited compared to wild studies [19,20]. Increasing the focus of capuchin cognitive studies to wild individuals was a welcome change in the past 20 years. The change was not easy, as many early studies on capuchins concentrated in forest populations (Amazonian and Atlantic Forest), which made experimental studies diffcult as capuchins are mainly arboreal in those environments and diffcult to observe and interact with. However, studies in those environments were successfully done. When, later, feld research was conducted in more open environments (savanna-like), mainly focusing on tool use, the quantity of data increased. Here I will review some of the work on cognition done on robust capuchins (genus Sapajus) in non-captive en- vironments, focusing on tool use. Primatologists and an- thropologists have much interest in this behavior, as it is a pivotal characteristic of humans. Understanding how pri- mates' physical cognition works (e.g. the physical features they use to select an object as a tool; or how they un- derstand the action of a tool), especially in a wild setting, helps us to understand better the evolutionary history and origins of tool use behavior. The same applies to the so- cial cognition related to tool use. For example, from whom do primates socially learn how and where to use objects as tools? How does information fows inside a social group? Understanding social learning of tool use is also of great interest because is an essential trait for ]] ]] ]]]]]] www.sciencedirect.com Current Opinion in Behavioral Sciences 46( 2022) 101170