A really good passage from a blog post on gender and coping with academia on The Valve, a Literary Organ:

On the first day, I like to create a disconnect between a hyperserious lecturing persona (marching around the room, brows knitted, with a syllabus full of dire warnings and contractual obligations) and deadpan declarations of my nurturing/feeling humanity ("I will write lengthy, caring, and thoughtful comments on your work. You will read and consider those comments before you complain about your grade, lest you hurt my tender feelings"). Some students laugh; others look concerned for my mental health. But there will be days during the semester when the conversation is warm, personally engaging, and fun, and other days when I’ll need to get serious or tough. I don’t want to risk damaging a reputation I’ve built up for one by pulling the other out of nowhere. In the end, my actual behavior is pretty reliable; it’s just the pose that changes.