While past research has shown that decision making styles significantly influence individual performance outcomes, little work has explored the effect of decision making style on group decision making. The objective of this study was to understand the effect of five decision making styles, task knowledge, and cognitive ability on group decision-making performance. Participants were individually scored for decision making styles, task knowledge, and cognitive ability, and then stratified into groups to complete a survival scenario task. Multiple regression analysis revealed that the spontaneous style of decision making strengthened the relationship between knowledge accuracy and performance, while the avoidant style weakened it. Furthermore, the rational style weakened the relationship between cognitive ability and performance. This investigation sheds light on the distinct contributions of individual decision-making styles and their interactions on group outcomes. The results encourage continued research on group decision making style and improve our knowledge of group performance.