A recent survey found that a third of us now dress casually for work every day.  But maybe you shouldn't.  Because according to several studies, how you look can affect your salary pretty drastically.

Specifically, it has to do with how attractive you are.  And you CAN make yourself more attractive by dressing up and not being a slob.  Here are three reasons to do it.

1.  You'll make more money.  In one study, hiring managers were shown photos of job candidates.  And on average, they were willing to pay the attractive ones 10.5% more.

2.  Dressing up makes you more confident.  Partly because of you feeling more confident, and partly because everyone around you THINKS you're more capable.  And when that's the case, you're more likely to get promoted.

It even applies to kids.  The same study found that teachers have higher expectations for good-looking kids, and devote more time to them.  Which obviously isn't fair.  But that extra time ends up boosting their self-esteem.

3.  Being attractive means you have good social skills.  Or at least people think it does, according to one study.  And the better you are at communicating, the more you make.

That's actually backed up by science.  According to Business InsiderResearch has found that social skills are a better predictor of lifetime earnings than how high your I.Q. is.