This study examines how leader gender influences cooperation and honesty in small groups, using incentivized behavioral tasks with 386 university students. While female leadership consistently fosters higher cooperation, this effect does not appear driven by gender identity or gender congruity. Followers of both genders cooperate more under female leaders, and expectations of honesty toward male and female leaders do not differ significantly. Instead, evidence suggests that individual attributes—rather than social identity—underpin this advantage. In a follow-up study with 124 participants, female leaders scored significantly higher on cognitive and affective empathy and demonstrated greater academic legitimacy (higher GPA), traits strongly associated with transformational and relational leadership. These characteristics, more prevalent among women due to socialization and structural factors, likely explain their superior capacity to promote prosocial behavior. Honesty patterns, however, remained largely unaffected by leadership, reflecting stable individual moral norms rather than role influence. Overall, our findings challenge explanations based solely on gendered prototypes and highlight the behavioral foundations of effective leadership. Female leaders’ relational and legitimacy-based strengths—not gender per se—emerge as key drivers of cooperative success, offering insights for designing inclusive teams and leadership development programs.