I was biking across the Longfellow (brrr) and wrestling with my skirt which was attempting to ride up above a decent height, when I had a further thought on taking the lane.
I was listening to Terry Gross interview John Hamm (of Mad Men) on Fresh Air a while ago, and she was remarking that the character of Don Draper has a way of crossing his legs that says "not only do I own the space I'm in, I own ALL of this extra space around me" It's just a subtly Alpha sort of thing to do- claiming territory with your body language. Maybe you had to hear how she said it, but it completely made me think of the attitude that you have to have when you take the lane.
I'm going to skirt around the gender issues of territorial marking, and how that may or may not relate to women's and men's attitudes towards vehicular cycling. However I think that there is an interesting parallel between body language and bike position language. Taking the lane says "here I am, this is MY space", whereas hugging the gutter is cringingly apologetic- "sorry I'm in your way, I don't mean to be, oops, sorry, don't mind me."
It doesn't have to be an aggressive thing- it's more about self confidence, and the respect that self confidence engenders in others. I get it, I understand how and why it works, but I also can completely understand how someone beginning cycling, perhaps a bit shaky, perhaps a bit slow, is not really going to have the self confidence to claim that extra space. And although I practice vehicular cycling much of the time, I think it's really important to have more protected facilities that will give people new to cycling a chance to get a little more comfortable with the feel of biking in the street and a sense of the rhythms of traffic- a chance to build the self confidence to take the lane.