Another case of over-eagerness getting the best of hopeful applicants, nodding your head is a universally recognised symbol of agreement, and one that people can use far too much of in an interview process. Whilst you might think that it creates a decent rapport, showcasing that the two of you are on the same wavelength, it actually dilutes and slightly confuses the interview as to where your actual common ground is. By nodding your head more and more, it becomes harder and harder for the interviewer to truly understand what parts of what they are saying you truly agree with. In some of the worst cases, it might even be mistaken for smugness as you give off the impression that you already know everything they are saying.