Offensive unpredictability and defensive tracking in intergroup conflict show sex-differentiated patterns

Intergroup conflict poses asymmetric strategic demands: acquiring resources through offense benefits from behavior that opponents cannot easily anticipate, whereas protecting resources through defense requires monitoring opponents and adjusting to threats. Analyzing behavioral data from 528 adults in a real-time offense-defense game, we found that offensive and defensive success were predicted by different decision patterns. Offensive success was associated with greater within-person contribution variability, a potential source of unpredictability, whereas defensive success was associated with stronger adaptive state-tracking of opponent behavior. These strategies aligned with sex-differentiated behavioral patterns: male participants showed greater variability and performed better in offense, whereas female participants showed stronger tracking and performed better in defense. Together, these findings identify dissociable behavioral strategies to success in offense and defense, offering a behavioral framework for understanding sex-linked variation in competitive social behavior.