Today I noticed a couple of my colleagues "dressed up" to teach (as opposed to being decked out in blue jeans) and realized that we've all changed our self-presentation over the years and have all started to look more professor-like. Did you notice such a shift among your cohort when you were in grad school? What was it like? When exactly did it happen? Was there a moment when it dawned on you that "Hey, X friend of mine looks like a professor now!"?
This is interesting to me, because actually, my experience was probably the reverse. I think that many of the people I knew dressed up to look "professorial" when they first started teaching, more so than when they had been doing it longer, and as they went along and gained in confidence, they grew more casual. One of the things that affects my perspective on this, though, is that when I started in grad school, my program had a LOT of "non-trad" students - people who'd been doing something else before they went back to grad school, sometimes for years. This made me feel like a babe-in-the-woods (for coming to grad school right after college - there were only two of us in my entering class of about 20-25 who did this, and the other person didn't come back after our first year) (though as a total aside, she ended up going back to a much more prestigeous program some years later, finishing quickly, and getting an excellent TT job, so yay for her!). I remember one of the grad students who'd started a year before me groaning and holding his head in his hands when he realized that I didn't remember one of the moments that had defined his life, the assassination of JFK (because, well, it took place six years before I was born).
Needless to say, this didn't exactly do wonders for my confidence.
But in any case, this kind of meant that a lot of my fellow grad students looked "professor-y" to me right from the get go, just because they were older than me. There were definitely those students who grew into the professor look, but until Mano's comment I hadn't really thought about their transition, maybe because it was the same kind of transition I underwent.
Anyway, I started teaching (TAing) at the ripe old age of 23, which was at most about 5 years older than my students; given that there were a lot of non-trad students at my grad U, students were regularly older than I. So I dressed up when I taught, to create some kind of distinction between myself and the students. Dressing up became a habit, one I maintain to this day (though I should add that "dressing up" generally means wearing skirts, hose [when the weather permits], and jewelry when I teach, and avoiding jeans and sneakers to teach in; I still don't own a suit).
However, if I did notice a significance change in my fellow students' personae, I think it came with being ABD. The dissertation-writing stage of grad school is significantly different from the coursework stage, and it really did seem to be the stage at which students had to grow up and become adults, because nothing external was driving them anymore. They had to organize their time and motivate themselves, and that requires a certain level of maturity. (Let me just add that I absolutely SUCKED at this. It took me five years to finish my dissertation, and while I was working full-time for a year and a half of that time, I spent overall probably about a year, spread over that five, staring at the walls accomplishing nothing. Interestingly, one of my friends, whom, I have to confess, I didn't consider an especially creative thinker, was so damned organized and focused that s/he finished really quickly and successfully. Which just goes to show that in the context of grad school, endurance is probably more important than brilliance - which is not to claim that I possessed the latter; I'm just a less dramatic example of the value of persistence. But I digress...)
I also don't mean to suggest that age automatically equals maturity in this context; the self-discipline necessary to complete a dissertation was something that my older colleagues had to learn just as much as I did. (Though some of them were definitely starting from a higher level of maturity than I was! And some of them were not...)
I think it was really the point at which people began seriously writing (as opposed to doing research) that marked a change - although traveling to archives to do research, especially when that research entailed leaving the country and living abroad for months at a time - doubtless had a lot to do with this. Especially once the writing starts to come together, and you start to present it at conferences - that has a big effect on how you present yourself, I think.
Of course, all this meandering is just based on my own experience, and on hindsight, no less. And I don't teach grad students, so my own experience is receding quickly into the past without any current experience to replace it. So I'd be curious to hear from people who do supervise grad students - do you see a point at which your students' personae change? And current grad students - when did you feel that you projected a different, "professorial" persona, if you can identify a specific turning point?