Interviewing 101: Looks Do Count
In general, a majority of scientists do not pay attention to their appearance or physical presentation. I believe that this behavior is based on both functional and philosophical considerations. First, because most scientists spend a majority of their time in laboratory settings, it simply does not make sense to wear "good clothes" to work. Second, many scientists believe that the quality of their work rather than their appearance is all that matters. Although these practices and assumptions may be useful for university settings, they are simply not acceptable in the industrial world. In fact, in the real world "looks do matter". To that end, if you are looking for an industrial or non-academic job, I have several recommendations for you to consider when you go on job interviews.
Acceptable dress for job interviews is suits or sport jackets for men and business suits or dresses for woman. If you are wearing a dress, I recommend that it be conservative and one that is not sexually provocative. And guys, please make sure that the color of your shoes matches the color of your suit or sports jacket and pants (brown and gray do not work). I recommend that all nose studs or rings be removed, men should not wear earings and all tatoos ought to be covered. Also, I highly recommend that your hair is washed and that you are clean shaven (except men with beards or mustaches) and if you are wearing makeup (women) make sure that it is appropriate for a job interview (not clubbing).
I know that some of you may feel that my recommendations are unreasonable and may inhibit you from being "who you really are". That said, the expected goal of every job interview is to get an offer so that you can become gainfully employed. To that end, being appropriately dressed for a job interview will not negatively affect your chances of getting an offer. Conversely, candidates who are inappropriately attired will likely diminish the liklihood of receiving a offer. However, an important thing to remember is, that once you are an employee, you can dress the way you want, put your nose stud/ring back in, wear your earings and flash your tats because it is difficult to get rid of an employee than it is to not extend an offer to a prospective job candidate!