An interesting article in the Sloan Management Review discusses a paper that shows what you wear can influence how you perform.

New research suggests that clothing can have an effect on our behavior if that clothing has a symbolic meaning and if we have the physical experience of wearing the clothes. 

Three experiments showed that knowing that you are wearing a doctor’s coat actually improved performance:

 In the first experiment, the researchers found that wearing a lab coat identified as a doctor’s coat did, in fact, increase subjects’ selective attention. In the second experiment, they found that people who wore the same coat but were told it was a painter’s coat did not have increased attention. And in the third experiment, they found that just looking at a doctor’s coat did not increase attention.

Here is the link to the research paper.