First impressions count – especially in interviews! For anyone who suffers from poor posture and/or lacks a good fashion sense, that little truism about first impressions is a painful fact of life. It also seems patently unfair, because it suggests that something as superficial as one's choice of suit jacket can trump everything else in an interview, including ability, experience, and suitability for the job.
But it can!

Call it what you will – a snap judgement, intuition, or sixth sense – but the initial impression that you make on your interviewer is lasting, and it often figures largely in whether or not you get the job. That's why it's crucial – in addition to being informed about the organization, showing up on time, having a firm handshake, etc. – to dress properly for an interview. Here are some things to keep in mind:

Stick to the Golden Mean – You're neither headed out to a gala event at the Ritz-Carlton, nor are you going to play baseball with the kids. Try not to overdress, and certainly don't dress too casually. However, if you're not sure, err on the side of over-dressing!

Choose Conservative Attire – Career advisors suggest that men stick to a classic cut suit, with a tie and black leather shoes – even if the actual job won't require such clothes. Career advisors recommend that women wear a skirt suit, or a dress with a color-coordinated jacket. (Yes, shockingly, in the career literature you'll find that skirt suits and dresses still have the edge over pants suits – at least at a first interview.) Avoid bold colors. Accessories that add a little personality to your outfit are recommended – within limits! You want to stand out, but not too far!

Avoid Scents – It's best not to wear a perfume or cologne, or to use overly scented soaps, because your interviewer might be allergic to scents. (And on the other end of the scent spectrum … make sure that you shower!) Of course, paying so much attention to one's dress probably seems a bit odd, because we're all taught that we shouldn't judge people based on appearance alone. True enough. But remember that an interviewer will be trying to get to know you and fill a position at the same time. And s/he will also have others to interview, so time will be of the essence.

Making a hiring decision on the basis of an initial impression may seem rash, but as Malcolm Gladwell says in his book Blink: The Power of Thinking Without Thinking, a lot can go on in those first few seconds after we meet someone new:

…It's thinking – it's just thinking that moves a little faster and operates a little more mysteriously than the kind of deliberate, conscious decision-making that we usually associate with "thinking."

Collected From Biospace