During an interview, you’re going to be mostly focused on the important content conversation you’re having with the interviewer.  But you’re also having a potentially revealing non-verbal conversation.  For instance, the non-verbal one will signal to you first when the interview should be over. 

Since we usually move closer to things we like and are interested in, and away from things that we dislike or are not interested in, look for changes in body orientation from your questioner.  If he or she suddenly moves in closer, then be prepared for an offer of some kind.  If he or she suddenly moves further away, then it may be time to leave.

There are exceptions to the general rule.  President Lyndon Johnson was famous for coming in very close to people he was trying to enlist on his side (most of the population, in fact).  He was a master at getting people to agree with him – especially other legislators.  They gave in because his invasion of their personal space made them so uncomfortable. 

Some interviews may try this trick to see how you stand up to the stress.

And there may be other reasons for motion that closes the distance, having to do with comfort, illustration of a point, or even an interruption from someone else.  Don’t jump to conclusions about body language too quickly; you should always be aware of the context and any environmental changes that might affect you and your interlocutor.  Once you’ve eliminated other possible options, though, be ready to act on non-verbal signals that tell you something about what’s going on in the mind of your potential colleague. 

You’ll instinctively know dismissive behavior when you see it; it’s very hard for even polite people to completely disguise their disengagement when they’ve made up their minds.  Similarly, if your questioner wants to make a connection, you’ll most likely sense that in the way that he or she orients his or her body in space relative to yours when you’re saying your goodbyes. 

The trick to accurate reading is to focus more on the other person than yourself.  That goes back to your state of mind going in to the interview.  If you want the job too badly, you won’t be able to get out of that frame of mind easily to become a cool observer of the body language in the room.  The best way to read the other person accurately is to be so well prepared and so comfortable that you can forget about yourself for that one important hour.