Theory and evidence suggest that everyday positive emotions may be potent factors in resilience during periods of chronic stress, yet the body of evidence is scant. Even less research focuses on the adaptive functions of specific positive emotions in this critical context. In the current research, 54 women with metastatic breast cancer provided information about their emotional responses to benefits received to test hypotheses regarding the social functions of gratitude. One set of analyses provide support for the hypothesized role of ego-transcendence in feeling gratitude upon receipt of a benefit from another person. As predicted, in a second set of analyses, grateful responding to received benefits predicted an increase in perceived social support over three months only for women low in ambivalence over emotional expression. These findings add to evidence regarding the social causes and consequences of gratitude, supporting a view of gratitude as an other-focused positive emotion that functions to promote high-quality relationships. Discussion focuses on the chronically stressful context as an important testing ground for theory on gratitude and other positive emotions.(PsycINFO Database Record (c) 2016 APA, all rights reserved)