We conduct an artefactual field experiment to study and compare the behavior of workers and students in a linear voluntary contribution mechanism in which subjects can assign immaterial sanctions or rewards to the other group members. We find that both students and workers sanction group members who contribute less than the group average, and reward those who contribute more. In both subject samples, the use of non-monetary sanctions and rewards induces more cooperation. The magnitude of the effect, however, is heterogeneous, as feedback has more impact among students who, contrary to workers, respond positively to sanctions. Students also tend to use sanctions more than workers. We discuss the implications of these findings for social cohesion, cooperative spirit and organizational efficiency in the workplace.