Confidence effects our ability to communicate. Therefore, it makes perfect sense to me that a teacher would be better at communicating ideas if they were dressed in a way that made them feel confident.
I suppose in many ways this is a bit of an empty article. The author really just seems to be saying that dressing up gets people to respect you more, which seems pretty common-sensical. That said, I did find his exploration as to why academics dressed so 'frumpily' to be an interesting one.
I agree with that. Also, if the attire made him feel different, I think it's likely he acted different when he wore it. I'm a pretty casual dresser, but over the years I've tried a lot of different styles of clothes and hair, some that made people confused at times, I think. Back in school I usually had long hair and a wide range of clothing styles. My brother was more traditional, -he wore college t-shirts, etc. For a few days I deliberately dressed like my brother. Almost immediately a girl in my chemistry class (that was a cheerleader, I think) began talking to me. It's just an anecdote, but I do think it makes a difference. I could definitely tell a difference between having long hair and short hair. Some merchants will obviously treat you differently. If a man in a suit or a man in rags begs my pardon in the street, I can't help but have a different idea of what they are going to ask me.
Doesn't that apply to everyone? It certainly works for me. In fact I noticed that even wearing a wristwatch or long hair has a subtle effect; certainly it is manifested in physical ticks. And when you get into piercings and tattoos the effect is very pronounced.
I've had terrible teachers that dressed sharp as a pin. The teacher who strikes me as the best teacher I've ever had (not a brilliant mind, but just good at helping people grasp complicated maths) was an old hippie lady. Instead of dressing nice she went to teaching conferences and read journals and what not.
He was emotionally immature, intellectually aggressive, often demeaning students ideas with harsh mocking criticisms. It was an introduction to Greek philosophy class, and many of the students were out of their depth and struggling. He came to class late every day, and kept us past time, another exercise of his power I suspected. I think his dress was definitely a tool to help him feel superior, feeling superior seemed to his M.O. Just a strange episode from my past that occurred to me when I was reading your post.