These are examples of behaviors that candidates have exhibited in interviews that have cost them not only the job they were interviewed for, but also any future opportunities with the same company. They from my own experience as well as stories told to me by other recruiters, interviewers, and hiring managers of my acquaintance.
1) Swearing in an interview. It is inappropriate to use foul language in an interview. It would seem to be common sense, but we recently had a candidate who dropped the "f bomb" during a lunch interview.
2) Making a racial slur. Even if you feel "sympatico" with an interviewer, remember that you are in a professional environment and that it is never okay to denigrate anyone on the basis of ethnicity, lifestyle, religion, marital/family status, etc. Ever.
3) Ask about *another* job you are interested in, not the one you are interviewing for. The time to do that is when you are talking to the recruiter, not when you are actually in the interviews. If you don’t want the job or are actually more interested in a different position, don’t waste everyone’s time trying to weasel your way into another position. This has happened twice in the last couple of months and all it does is turn the hiring manager off.
4) Pull your cell phone out to either check your mail/texts or take a call. One of my colleagues was sitting in the final interview with the General Manager and the candidate. The candidate’s phone rang and he took the call. It cost him an offer for the job.
5) Moderation in your personal presentation. A team once went with another candidate because one guy had on so much cologne it took a whole day to air out the interview room.
6) Maintain *eye* contact. From a female friend of mine: At a former employer, I was once part of a panel interview with a candidate. The entire hour, he did not look at the face of any interviewer…he only looked at my chest.
7) Dress for success. "Best ever- candidate shows up to interview in full Japanese kimono outfit. " There is nothing wrong with being proud of your cultural heritage, but part of the interview process is making sure there is a cultural fit. If in doubt, ask the recruiter what the dress code is for the interviews.
8) Personal hygiene is a must: I had one guy pick his nose during and interview and then ask to shake hands.
9) Communication skills: Candidate talked way too much about his personal life during the interview. Just because *you* think it’s a positive that you do" X", that doesn’t mean other people will agree.
10) Market yourself positively. When interviewing a candidate, we got to the question "tell me about your weaknesses" , and she said she has never been able to throw away a piece of paper, and has organized stacks of paper all surrounding her desk, and then kept going on about other weaknesses….we asked her to stop and tell us about some of her strengths.
11) Preparing for the job and interview (i.e. a portfolio): My company was interviewing a web developer who came in for a group interview. I Googled him to see what kinds of work had his name on it, and a blog site popped up. I went to it and it was broken; a syntax error in a file. I brought it to his attention during the interview, and he said basically that he hadn’t seen the need to fix it. A few days later it was still broken.
It truly amazes recruiters, interviewers and hiring managers what some candidates will (not) do during interviews.