We propose a methodological paradigm for testing the functions of an emotion using culture. Taking gratitude as an example, we predicted that, for gratitude to function, people in Confucian cultures would use self-improvement (cultivating personal skills and living up to social roles) to communicate gratitude, whereas people in individualist cultures would use bodily contact. Indeed, whereas Taiwanese (Confucian) and American (individualist) participants showed gratitude similarly via verbal acknowledgment and reciprocating kindness (Studies 1 and 2), participants from both countries also demonstrated their uniquely hypothesized respective cultural behaviors when showing gratitude, prioritizing such behaviors more in daily life than did participants from the comparison culture (Study 1). Additionally, compared to the gratitude demonstration uniquely hypothesized for the comparison culture, American and Taiwanese participants reported applying their unique cultural demonstrations similarly to applying the a priori culturally similar demonstrations (e.g., reciprocity; Study 2), implying that the culture-specific demonstrations are as common as the nonspecific within the respective cultures. Finally, Americans perceived gratitude through others' bodily contact (vs. self-improvement) similarly to perceiving gratitude through reciprocity-that is, the 2 behaviors communicated similar information for Americans-whereas it was self-improvement but not bodily contact that communicated gratitude similarly to reciprocity for the Taiwanese (Study 3). Together, this research deconfounds gratitude's underlying relational function from its ostensible manifestations and demonstrates the utility of studying culture to further functionalist emotion theories. We also developed and demonstrate a new method for debiasing cross-cultural comparisons along the way.