In an ideal world, no one would. However, in the real world, we form an impression of a person in the first 30 seconds to 2 minutes after we meet him or her. Okay, you may be thinking. I'm willing to sacrifice a little upfront pr for comfort since I'll have the chance to impress them later with my business acumen. Don't count on it. Recent research suggests that, not only are first impressions hard to change, if someone makes a negative first impression on us, we're less likely to seek that person out again. So while initial impressions can be changed, human nature works against us having the opportunity to do so.
Why do Clothes Matter?
You are seen before you are heard. As a result, before you open your mouth, your appearance has already spoken volumes about you. Whether the other person realizes it or not, s/he has already made assumptions about your competence, intelligence, judgment and so forth. In fact, according to Dr. Albert Mehrabian's research, our visual image (physical appearance and body language) accounts for over half of the first impressions we create.
Are People That Superficial?
Yes we are, although not quite in the way you might think. Because we have so much going on in our brains, our ancestors learned to make mental shortcuts, i.e., simple rules to help us categorize and make quicker decisions about things we encounter. Unfortunately, these often lead to unconscious biases where we tend to see what we expect. In other words, people are affected by your appearance, whether or not they realize it, and whether or not they think appearance is important.
So here's how this works when it comes to what we wear. Two psychological shortcuts people use are the "halo effect" and its opposite, the "devil effect." The "halo effect" is our tendency, if our first impression involves one or two positive things about a person, to develop a generally positive overall impression, sometimes in spite of later evidence to the contrary. And, of course, the "devil effect" is the opposite side of the same coin.
A Lapse in Judgment or Fashion Faux Pas?
In other words, the reason what we wear to work is important is because of what our attire represents. What's really being evaluated by what you wear is your judgment - how well you understand the social rules of the context you are in and whether or not you are willing to follow them.
An attorney who shows up for court has the same skill level whether he's dressed in blue jeans or business formal. However, he is likely to get a very different reception from the judge, who is likely to assume a Levi-clad attorney either doesn't know the social codes or doesn't care about them. And, from a client's perspective, a professional who doesn't "look" like one isn't likely to inspire confidence that she can excel as one.
The Bottom Line
No, it shouldn't matter if a woman wears a tight, pencil skirt or a man wears Birkenstocks and Bermudas as long as s/he excels at work. But know that to some people, it does.