Competitive bonuses are commonly used to promote higher productivity in the workplace. Yet, these types of incentives can have subsequent negative spillovers on coworkers’ prosocial behavior. We revisit this question in a lab-in-the-field experiment and examine whether competition negatively affects Social Value Orientation (prosocial attitudes) in addition to contributions to a public good (cooperative behavior). By considering the context of a developing country, we contribute to replicating previous findings in White, Educated, Industrialized, Rich, and Democratic (WEIRD) samples. We find that when the payment dispersion between winners and losers is high, competition reduces both cooperation and prosocial attitudes compared to a threshold payment. Mainly winners cooperate less under competition. A comparison with a random payment scheme suggests that rivalry might partly explain the crowding-out effect in other-regarding preferences. Under low payment dispersion, competition does not affect cooperation or prosocial attitudes.