The present research looks at how people interpret power in negotiations based not just on control over objective resources but also on behavioral expressions of dominance as signaled through affective language in the limited-cues environment of electronically mediated communication. We further explore whether those interpretations of dominance shape negotiation outcomes. The results of an experiment, along with the linguistic analyses of the e-mail messages themselves, indicate that negative affective expressions (anger) online positively influence perceptions of dominance, while displays of positive affect (happiness) can signal the opposite, especially when coupled with low resource power. Moreover, we find that anger displays in e-mails can influence individual gains positively, while perceptions of dominance mediate the relationship between displays of happiness and individual outcomes. Implications are discussed.