We study the interaction between horizontal (peer) and vertical (manager) social factors in workers’ motivation. In our setting, individuals work using open-plan desks. Using a natural experiment, we identify a sharp increase in workers’ productivity following the occupation of adjacent desks. We link this peer pressure effect to two key aspects of the worker-manager relation. First, we find stronger peer pressure when managers monitor workers less. Second, we find stronger peer pressure among workers performance-evaluated by the same manager. In a set of counterfactual exercises, we illustrate how organisations could take advantage of these interdependencies to increase worker productivity.