This paper presents a large-scale analysis of emotions in conversations among Wikipedia editors. Our focus is on the emotions expressed by editors in talk pages, measured by using the Affective Norms for English Words (ANEW). We find evidence that to a large extent women tend to participate in discussions with a more positive tone, and that administrators are more positive than non-administrators. Surprisingly, female non-administrators tend to behave like administrators in many aspects. We observe that replies are on average more positive than the comments they reply to, preventing many discussions from spiralling down into conflict. We also find evidence of emotional homophily: editors having similar emotional styles are more likely to interact with each other. Our findings offer novel insights into the emotional dimension of interactions in peer-production communities, and contribute to debates on issues such as the flattening of editor growth and the gender gap.