There is some subjectivity to this topic. Obviously what you wear to work will depend on what your job entails. I’m going to be speaking from the perspective of the day-to-day programmer. I’d say probably about 15 years ago (give or take) you would typically see programmers dress anywhere from business casual to business professional (i.e. dress shoes, button down shirt and a tie). Currently I wear business casual which is a nice collared shirt, khaki’s and nice shoes, but that is because it is the dress code of my firm and I will adhere to those policies. Personally, I don’t buy into “the better you dress the better you work”.
I could never wear a suit and/or a tie to work everyday and be as productive as I am when I wear jeans or even lounge pants. Honestly the more comfortable I dress the easier it is for me to focus on writing code. When my brain isn’t distracted by the attempted asphyxiation of a tie or the constricted nature of some dress shoes, that extra energy can be directed toward problem solving and writing code.
Honestly, I think that is one of the reasons why I am actually more productive on the days when I need to work from home. Some may argue that working at home presents more opportunities for distractions, but that isn’t the case for me. The fact that I am sitting in a far more comfortable office chair and wearing far more comfortable clothes is a better environment for my brain to focus. After all, it is the same desk and chair that I use when I do any kind of extra curricular programming at home.
I do understand the rationale for wearing professional clothing. In fact in college I had a course on conflict resolution and negotiation and we actually had an exercise over this exact topic and I was on the side that defended professional dress. I did the research on professional dress but, despite what I found, I still believe that the more comfortable you dress the easier it is to be more productive.
/cheers