A good looking, well dressed candidate confidently walks in on time, smiles, looks you in the eye and warmly shakes your hand. You exchange pleasantries for a few moments and you can feel yourself beginning to relax.
You think "Oh good, they seem like a great candidate!" So you might be tempted to begin talking more. You know, to get them interested in the job.
Except, of course, you don't know a thing about them yet.
Interviewing is full of traps like these.
We're drawn to good looking resumes that fit our mental picture of what the resume should look like (regardless of who actually wrote that resume, or whether people from other backgrounds might be more qualified).
We're seduced by appearances in the interview (regardless of the fact that interviewing ability does not predict anything about the candidate's ability to do the job).
We're most comfortable with people who are "like us" even though teams are strengthened by diversity.
Traditional interviews are 80% theatrics (performance art) and 20% substance--your instincts will routinely fail you unless you methodically guard against your unconscious biases. Don't wing it.