Conflicts are typically considered stressful and therefore can elicit strong physiological reactions such as increases in heart rate or blood pressure. Thus far, surprisingly little research attention has been paid to how psychophysiological stress responses affect the way conflicts are managed. In this chapter we address this issue and focus specifically on intragroup conflicts. To that end, we first review the intragroup conflict literature, concluding that groups tend to be hurt by relationship and process conflict, but may benefit from task conflict under certain circumstances. Next, we discuss four studies in which we applied the biopsychosocial model of challenge and threat (BPSM; for example, Blascovich, 2008) to understand how psychological and cardiovascular markers of challenge and threat states are related to how people deal with task conflict during joint decision-making tasks. We describe how across the four studies we found that people tended to hold onto their initially preferred decision alternatives more strongly when they exhibited a threat (vs. challenge) states during a task conflict. We also discuss how in many, but not all, cases this will lead to suboptimal decisions.