How is it we seem to know when someone is watching us, even if our backs are toward them?

I believe this is a case of confirmation bias. We feel that someone is looking at us, so we look. When the person is looking at us, our brains count it as confirmation that our suspicion/feeling was true. If the person was not looking at us, we don’t register it as a failed intuition. We accumulate our “hits” and remember them, while not doing the same thing with our “misses”.

Nothing more than Paranoia™.

http://youtu.be/pDvm_MlgxdU
^ That just happened.

I think it is instinctual based on the days when a Sabre tooth tiger or other predator was stalking us. I once felt a presence and turned around to see a Mountain Lion about 6 feet away from me behind my barn one summer night after dark when I was checking on my animals in their barn.
Seriously, I turned my flashlight on it and all I saw were two enormous, glowing green eyes staring back. The cat and I stood frozen for about 30 seconds and then it just turned and vanished into the brush.

I KNEW something was staring me down. haha

I wonder if it has to do with registering small sounds, or the lack of one when there was one before. Like when you hear the sounds of people shuffling by or coming up behind us but the sound comes to a sudden stop.

Or we are alone and suddenly we hear someone else. We look at them and they look at us. Why for the same reason we looked at them. We have to acknowledge that we saw them so they don’t have the ability to surprise us any longer.
I think whenever we feel vulnerable our senses for our environment is heightened. At least I know it is for me. I tend to be more aware of people walking behind me when I am walking alone than when I am in a group.

GA @Pandora.