If you love dressing for Casual Fridays, be careful. Because what you wear can actually influence how productive you are on the job! 

Researchers at Northwestern University’s Kellogg School of Management observed volunteers while they worked and measured how thorough and focused each person. 

In one session, volunteers wore their normal street clothes. In the second, they were asked to wear a lab coat. The result: Everyone did a better job when they were wearing the lab coat! 

Why? Study coauthor Adam Galinsky says we mentally attach meaning to clothing. So, wearing a lab coat makes us feel smarter, and makes us more precise.  Just like wearing a dark blue suit makes most people feel more powerful and capable. 

But that doesn’t mean you have to forego all of your khaki’s and jeans. It’s your own perception of yourself that’s important. For example, some women associate high-heels with power and intelligence. But others think stilettos send the opposite message. 

Bottom line: If you have clothes in your closet that you think look “smart” – odds are they’ll make you work smart, too.