Recently I've read some posts about what to wear the first day of class, what to wear if you're a young-looking studentesque female professor, and what to wear in general if you don't fit the stodgy white male professor image. Most people say jeans are a big no-no because students won't take you seriously, will walk all over you, etc.
The first day I taught at Bowdoin College I wore jeans. I didn't care if students cared what I wore. I knew no matter what clothing I taught in, I would still have to earn their respect because: I am female, I am young, and I am also very likely to be mistaken as a student. Plus, even though it was the East, formality wasn't part of the atmosphere. How many benefit-of-the-doubt points could I expect to earn from donning a suit? Not many.
I am a firm believer that nonverbal communication (including clothing) is incredibly important in all sorts of situations. I ought to know: I teach an upper-level seminar in the subject. The sage advice of Polonius: The clothing oft proclaims the man, rings true to some extent. However, any initial bonus points you earn from dressing up will evaporate when you're subsequent behavior doesn't match. If you let your students walk all over you, regardless of whether you're wearing a suit or not, they will.
At W College, I rarely wore jeans. I rarely wore my beautifully tailored Ann Taylor suits either. I strove for somewhere in between. WC is a seriously informal place. Students and faculty usually address each other with first names, faculty rarely wear suits (ditto for the administration), and the whole place runs like butter this way.
Today I sat in on the first day of an Intro Psych class a former colleague teaches. Given that I won't be teaching this year and have few responsibilities others than finishing my dissertation, I look at this time as an unpaid pre-doctoral sabbatical. My own intro class has been the same for three years; I need some fresh ideas. My colleague was more than welcoming of my presence in class (I okay-ed it with him first). It is always neat to see how someone else does it. I very much recommend watching others teach. It doesn't matter if they are horrible or so outstanding you think you should switch careers because you'll never be that good; you will learn and gain inspiration for improving your own teaching. If you can watch master teachers, they are certainly going to provide the best fodder.
By the end of the semester I will be well-prepared to revamp and revitalize my class.
By the way, this prof wore jeans, a T-shirt, and sneakers. He hardly looked like a professor at all.
Perhaps it's just small liberal arts colleges that make it possible for us to get away with this informality, but I wouldn't want to work anywhere that had a dress code that made me feel uncomfortable or reinforces the notion that clothing makes up for lack of behavioral authority.