To examine the relative influence of cultural and temperamental factors on emotional response, we compared the emotional behavior, reports of emotional experience, and autonomic responses of 50 European American (EA) and 48 Chinese American (CA) college-age dating couples during conversations about conflicts in their relationships. EA couples showed more positive and less negative emotional behavior than did CA couples, despite similarities in reports of emotional experience and autonomic reactivity. Group differences in emotional behavior were mediated by cultural (values and practices) but not temperamental factors (neuroticism and extraversion). Collapsing across groups, cultural factors accounted for greater variance in emotional behavior but lesser variance in reports of emotional experience compared with temperamental factors. Together, these findings suggest that the relative influence of cultural and temperamental factors on emotion varies by response component.