"A number of studies have revealed that dressing well increases your performance and heightens others' impressions of you. For example, wearing clothes that make you feel important or intelligent can change the way you interact with others as well as your cognitive functioning. It can even make the difference between booking a couple or not.
What's more, other people will make different assumptions about you based on the way you dress. This means you can make yourself smarter or more powerful based on your clothes alone - not "look" smarter or more powerful- but actually make you smarter and more powerful. A change of wardrobe can help you get the job you want, the deals you want, the recognition you want, and even the mate you want. It's that powerful.
The symbolism behind what you wear has more of an impact on your behavior and self-confidence than the clothes themselves. These studies show that when you wear an outfit that you associate with intelligence and power, you're likely to do better and feel better than when wearing clothing that you associate with sloppiness or low-skilled work.
However, not everyone needs to jump into an Armani suit to feel good about themselves. Dressing in clothes that make you feel YOUR best benefits your confidence the most, whether you're wearing a football jersey or a designer suit."