Im not a human resources expert, but I have been on several hiring committees and have been involved directly in the hiring decisions at several organizations.

What Ive learned is that usually the decision boils down to a few top contenders with qualifications of fairly equal caliber. When more than one applicant is suitably qualified for a position, how is the decision made?

Many times, the candidates help us make the decision by unknowingly disqualifying themselves!

Here are the three most common ways otherwise qualified candidates have eliminated themselves:

1. Making inappropriate comments during the interview. This includes disparaging comments about a previous employer, using swear or borderline swear words, or saying anything unkind about former colleagues, clients, or constituents. I was astounded recently when a candidate who had aced his first interview referred to someone as a bastard in his second interview!

2. Being or doing anything even slightly repulsive. Remember, even if it doesnt seem repulsive to you, it may be repulsive to others. I was in an interview once where the candidate blew her nose and then wadded the tissue into her empty water glass. This meant someone on our team would have to pry the tissue out with her fingers before the glass could be washed! In our discussions afterwards, the interviewers agreed that this lack of consideration eliminated the candidate from the running.

3. Failing to wow the interviewers during subsequent interviews. Sometimes candidates feel overly confident after theyve been asked to come back for a second interview. Confidence is a wonderful thing, but the interview process isnt over yet. Its not yet time to relax. Dont be overly familiar or presumptuous. And certainly dont start negotiating your salary or vacation days just yet.

The candidates that Ive seen ultimately land the positions they were going for have been relaxed but not overly so, confident but not cocky, and have projected a team-like attitude that includes sensitivity towards others, and just general like-ability.