This is a new paper, published a couple of weeks ago. (Sorry if it's been mentioned before, I couldn't see a related thread.)
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0104880
Principal findings:
We find that administrators maintain a rather neutral, impersonal tone, while regular editors are more emotional and relationship-oriented, that is, they use language to form and maintain connections to other editors. *A persistent gender difference is that female contributors communicate in a manner that promotes social affiliation and emotional connection more than male editors, irrespective of their status in the community. Female regular editors are the most relationship-oriented, whereas male administrators are the least relationship-focused.* Finally, emotional and linguistic homophily is prevalent: editors tend to interact with other editors having similar emotional styles (e.g., editors expressing more anger connect more with one another).