In a study of status uncertainty and online gift exchange, I argue that deviations from reciprocity in social exchange is partly affected by tacit interpersonal dominance competitions that are more likely to arise when actors cannot clearly perceive relative status differences. Using an event history model on gift exchange records of Korean social media users, I find that when an individual’s online popularity is not clearly higher or lower than an exchange partner’s popularity (i.e., status ambiguity), she tends to delay gift reciprocation, arguably as a tactic to enhance dominance in the dyadic relationship. This work highlights status competition as a countervailing interactional tendency to status homophily (i.e. more frequent interactions among status equals) and calls for closer attention to different social-psychological mechanisms that drive social interactions. This paper entitled, “Reciprocation under Status Ambiguity: How Dominance Motives and Spread of Status Value Shape Gift Exchange” was published in the journal, Social Networks.