Body language" is the current number one explanation for non-verbal communication. I'm sure you've been exposed to some of the theory: folded arms means you're closed to friendly advances (or that you are being determined or have a shoulder injury ...); toes pointing at someone means you like them (or that your foot keeps hitting the wall or table leg or that your reclining and twisted in your seat ...); etc. The hippies used to talk of non-verbal communication through "vibrations" (e.g., Those are good vibes, man). Now that science has verified that everything living (and non-living) emits an electro-magnetic energy field, some are once again talking about communication through vibrations, but this time it is electromagnetic wave-length frequency vibrations.