My main research project consists in studying the evolution of economics in animals. This project is born from the observation that humans share, barter and trade to an extent not seen in other species. Transfers of services or even food can be seen in non-humans, but they are not always reciprocated. One can thus question whether they rely on similar cognitive calculations as bartering humans do. To answer this question, I study comparatively non-human primates (great apes and monkeys), corvids and canids, using experimental techniques applicable to all species (the exchange task). I test the capacity of each species to anticipate or plan for a return, to risk losing food in an exchange with a human partner, to maximize gains by investing differently according to prospective returns. I also investigate how economical skills emerge in humans by using a developmental approach. Studies are conducted with several European collaborators and host institutions : The Max Planck Institute, Germany ; the University of St-Andrews and RZSS, Scotland ; the Konrad-Lorenz-Institute in Grünau, Austria.