Does Cooperation with Others Reduce Risky Gambling Behavior?1

Social relationships are highly salient for problem gambling. This study investigated the effect of others' presence or cooperation with others on risky gambling behavior among healthy undergraduate students. Based on the findings that individual differences moderate the social facilitation effect and team performance, we also focused on personality traits. A total of 36 participants completed the Game of Dice Task (GDT) in three conditions, within a crossover design: the sole condition (each participant conducted the GDT individually), the parallel condition (each participant conducted the GDT in parallel with another participant), and the cooperation condition (participants conducted the GDT at the same time and were told to consult with each other). Before the experiment, all participants completed the NEO Five Factor Inventory. The results showed no significant differences among the sole, parallel, and cooperation conditions in terms of risky gambling behavior. However, safer gambling behavior in the cooperation condition was significantly and positively correlated with conscientiousness. These findings suggest that a new harm‐reduction strategy focusing on cooperation with others while gambling could be developed.