Providing inclusive environments has become a primary tenet of modern societies and organizations. The use of gender-inclusive language (GIL) is often considered an instrument that can promote inclusion, yet little is known about its effects on relevant economic behaviors and on gender gaps in the labor market. GIL avoids the masculine “default” (common to many languages) by either explicitly mentioning both masculine and feminine (pro)nouns, or replacing them with nongendered (pro)nouns. Here we study the causal short-run impact of GIL on competitiveness and leadership in the laboratory, with two different language samples—English and German—which differ, among other things, in the extent to which gender is embedded linguistically. We vary GIL in experimental instructions across three treatments ([Formula: see text]): a masculine baseline condition, a condition with feminine and masculine (pro)nouns, and a condition with nongendered (pro)nouns. We find that participants who identify as female and participants who identify as male compete, stand for leadership, and vote on leader candidates similarly across all treatments, in either language. Furthermore, we find no treatment differences in participants’ feelings of inclusion and perceived entitlement. In sum, there is a lack of support for GIL having short-term causal effects on competitive and leadership behavior and inclusion perceptions. This paper was accepted by Marie-Claire Villeval, behavioral economics and decision analysis. Funding: This work was supported by the Austrian Science Fund [Grant SFB F63], UK Research and Innovation [Grant MR/T020253/1], the University of Exeter, and Regensburger Universitätsstiftung Lucia and Dr. Otfried Eberz. Supplemental Material: The online appendix and data files are available at https://doi.org/10.1287/mnsc.2024.04342 .