Quite agree, Path - many animals are already recognised scientifically as using being able to sense and react to forms of electro-magnetism through specialist organs (sharks), or else construed from extreme behaviour (migratory birds).
However, each and every one of us gives off an electromagnetic field, which means at some level, each and every one of us will be sensitive to changes to the environment and people around us. Significant changes in these fields should have a similar impact on ourselves.
The problem being, that such a sense of such seems to operate on a sub-conscious level more than anything else. Hence people associating these sensations to "gut feeling" or "instinct" or "psychic ability" or similar.
Personally, I think in many instances, we are just giving conscious consideration to unconscious stimuli - that we really can feel these things, but are not always sensitive to them.
Additionally, the whole industry of tape recording showed that sound and vision could be recorded into magnetic particles - and yet in the natural world, many rocks around us will contain significant metallic minerals.
There are a couple of places I've stood, out in open countryside, only to get a strange panicked sensation - a feeling of a need to run away. There's a sense of something bad, to escape from. Each time it happened, upon leaving we discovered we'd been stood on a known battlefield, but unknown to us beforehand.
Additionally, going back to earlier, I do not (yet) think it is possible for humans to read minds directly, but you can certainly "feel" people and react to them as a form of empathy. Learning to be sensitive to empathy can take some time, and can be hard to do, but its a fascinating if somewhat useless feeling experience (what can you do with Empathy to help the world?).
That's not to say such a suggestion explains everything attributed to forms of psychic phenomena - but certainly I think humanity really does have a "sixth sense", one very much in common with the rest of the animal kingdom, which is a sensitivity to electromagnetic fields. While we may not have a known specialist organ for detecting and using such information, I think it's difficult to argue against such sensitivities as existing.
Interesting thing about electromagnetic fields - they are theoretically infinite. Every single part of the universe is connected by electromagnetic and gravitational fields. Imagine that - a universe filled with invisible strands connecting everything, and that even our own actions on earth could - somehow through that process - influence some other event half way across the universe.
Thinking on - Ley Lines I would suggest are potential markers of the earth's magnetic field - certainly to some degree. Again, the earth immersed in its own web of life - a field with very real contours and lines.
Ah, I'm remembering again.