Reports of shadow people have existed throughout history. The observer generally reports seeing a dark shadow that resembles the form of a human which appears and moves of its own accord. The figure does not have distinguishable facial features and may be either much smaller or larger than a human. They are often noticed as movement from the corner of the eye, sometimes disappearing when the observer turns to investigate...

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Castaneda calls them Flyers, if i translated it correctly from my linguo

[ravinclaw]

Many paranornal investigators think that shadow people are simply human spirits who lack the energy or desire to fully manifest.

[ViciouslyMe]

I still say that some sighting of "shadow people" are simply beings that choose for usnot to see their true form.

[ViciouslyMe]

Of course not, it is definietly something that needs to be looked more into.

[CaptainClyde]

When I was a little walrus, I used to see things out of the corner of my eye. Tiny, little, hunched things, hiding everywhere.

Lurking in the shadows.

I don't remember if anyone ever gave an explanation, although this sounds reasonable. But really, they were everywhere.

I hope they never come back...

[ravinclaw]

I like clyde, dont know why, just cant help it. LG is absolutly corect though. Shadow people can be many things. I also have to agree with Vicious. There are things that interact with us that would rather remain unknown.

[heckco]

i think shadow people are left over echos of human souls. They are suppose to be our mirror oppose of our inner soul. Would make sense why always around humans and we can only see certain  shadows ghost. 

[Delamorte]

Shadows are Demons.. Not strong demons but Sub-demons.. They observe and report.

@Delamorte, no. They're not. At least, not all of them. Hard to nail down in specific what they are, but... Unless you've got firm proof, I'd advise against making assumptions.

I agree mostly with the theory that they are just manifestations of human emotion or energy.