Let's face it, people are assholes. It's in our nature. It is so much easier, and safer, to label someone based on what they look like. Racism and prejudice are just parts of nature. But how can you affect the way someone labels you, and why is it important what their first impression is? We decide whether or not we are going to conduct an interaction with someone based on their appearance. It is an evolved trait that has helped the human race survive for millions of years. Imagine this, you are in a bank. Three men walk in wearing all black clothes and ski masks. You run for the nearest cover. This is your assumption that they are bank robbers and are ultimately going to cause you harm or grief. While in the scenario I had just described this trait might have saved your life, it also appears in our everyday interactions with probable inaccuracy and negative repercussions. Walking down the street, we automatically in gage this trait, labeling everyone we see. Therefore, it is important that we make a good appearance. Now, while you can't go around wearing your best clothes every second, it is imperative that you use adequate timing. Going to a social event of any kind is cause to dress up.
Looking at these two men, who do you think is the more interesting person? You did it again, you just made assumptions based on their looks. But that can be used to your advantage. After someone makes a positive assumption about you for dressing nice, it will be much harder for them to negate that original thought due to some undesirable comment you might make later. Dress up.