Shadow People: Who or what are they?

That question has been asked by paranormal researchers for many a year now, and despite some evidence to suggest what they could be, we are really no closer to answering this question than when it was first asked. As with other entities, present scientific equipment and practices make it extremely difficult to answer this question to the satisfaction of most researchers, and let's face it, because of this most scientists refuse to even acknowledge that they could exist because they can't get a tangible sample of them under a microscope.
Please don't misunderstand me, science has advanced the knowledge of man greatly over the years, but it only accepts what can be seen, touched, and examined in a physical sense. If it exists beyond this realm of "physicality" it is basically dismissed as imagination or written off as non-existent altogether. On the upside of this, science is beginning to discover that not all things that exist can necessarily be handled and examined under a microscope. One example of this is wind, science accepts the concept of wind, it cannot be gathered and examined under a microscope, yet is accepted based on observations that can be measured with other scientific devices, devices developed over the years to measure something that has no real substance, yet does exist.
I see no difference between the existence of wind, and the possible existence of ghosts, shadow people and other assorted entities other than the fact that the necessary scientific devices needed to positively identify them just hasn't been developed yet.
I'm rambling, so let's get back on the subject here...

Shadow people (also known as shadow men, shadow folk or shadow beings) are a purported supernatural phenomenon in which observers report seeing a dark form at the edge of their field of vision, that disintegrates, or moves between walls when noticed, usually within a split second.
Reports of Shadow People are similar to purported ghost sightings, but differ in that Shadow People are not reported as having human features, wearing modern/period clothing, or attempting to communicate. Witnesses also do not report the same feelings of being in the presence of something that 'was once human'.
Some individuals have described being menaced, chased, or (more rarely) attacked by shadow people, there have also been reports of Shadow People appearing in front of witnesses, or lingering for several seconds before disappearing. There have also been some alleged photos taken of these Shadow Folk.
Most accounts of Shadow People describe them as black humanoid silhouettes with no discernible mouths, noses, eyes, or any expression whatsoever. Though purported witnesses have also described child-sized humanoids, or shapeless masses. Some reports also include glowing red eyes. Generally, they are described as lacking mass, though their specific nature varies from a two-dimensional shadow to a vaporous or distorted 3 dimensional form.
Their movement is often described as being very quick and disjointed, or they may first move slowly as if they were passing through a heavy liquid, and then rapidly "hop" to another part of a witness' surroundings. Some witnesses describe this movement as though the shadow entities they have seen "danced" from one wall to the next. Typically, encounters are accompanied by a feeling of dread, although this may be simply distress of viewing such an event.

Some have odors associated with them while most don't. These accounts have been reported all over the world. However reports of beings fitting the description of Shadow people have been recorded for centuries in literature all over the world.
Accounts of shadow people are, in many respects, different from accounts of ghosts. Ghosts are said to be the disembodied spirits of people and are usually said by to take on the appearance of people, orbs, ectoplasm or mist when seen.
While ghosts are often said to resemble actual people, accounts of shadow beings generally do not.
Direct visual contact is rarely reported by most eye witnesses of shadow people. They are said to usually disappear before they can be seen clearly, and are seen "in the corner of one's eye." These beings are also said to often appear in mirrors.
There are many proposed explanations of this phenomena.
One of the more creative theories is that shadow beings are manifest thought forms, meaning that they are collections of negative psychic energy from areas where traumatic events have taken place and evil people frequent. The negative psychic energy begins to manifest and takes on form and motive, thriving on fear and negative emotions for sustenance.
Shadow beings have also been described as forms of ghosts, demons, inter-dimensional beings. The most popular explanation seems to be that they are some sort of other-dimensional beings whose dimension of origin occasionally overlaps with ours, which is said to explain their ethereal appearance and fleeting nature.

As with most supernatural phenomena there is usually a proposed logical, scientifically valid explanation for credible experiences that neither vilify eyewitnesses, nor require violation of generally accepted scientific principles. Here are a few of those proposed explanations:

There is a condition known as hypnogogia (waking sleep) which amounts to a state of semi-consciousness in which a person can be thinking clearly and yet perceiving images that are being dreamed. This state is probably responsible for most so-called supernatural experiences by honest, rational people.

It has also been proven recently that areas with erratic or powerful electromagnetic fields can interfere with the electrical impulses or firing synapses of the human mind, thus influencing people subjected to such environments over time to believe that they are hearing or seeing ghosts, aliens, or perhaps shadow beings. Such environments include old buildings with substandard wiring, power plants, and areas with naturally occurring strong magnetic fields.

Under the right conditions, electromagnetic fields can interfere with the functions of the temporal lobe of the brain; creating altered states of perception in which auditory and visual hallucinations can occur.
Using electromagnetic fields, researches have been able to recreate many of the experiences reported during paranormal encounters under laboratory conditions (including those of Shadow People). Researchers have also documented correlations between variances in naturally occurring magnetic fields and areas where paranormal events have been reported.

Perhaps the only aspect of alleged eye witness accounts of shadow people that remains difficult to explain in objective scientific terms is the similarity of the beings being seen in these alleged accounts, especially the "tall man with a hat" that is reported as often by 4 year old children as it is with adults.
In most instances, witnesses report seeing Shadow People in the peripheral areas of their vision. This area of vision is linked to the areas of the brain that recognize patterns, however it provides less detail to the brain than Macula (Center-forward) vision. This can lead to a condition know as Pareidolia, in which the brain incorrectly interprets random patterns of light/shadow or texture as being familiar patterns such as faces and human forms. The same condition can also be observed in Macula vision in low light conditions, or when viewing a complex but random image. A common example would be perceiving a shadow, thrown by an item of furniture in a darkened room, as being a person.

These are just some of the "accepted" explanations for shadow people, but by no means all of them.
I encourage you to do some research and come to your own conclusions on what you think they are.
 

Written by HPIR Tech Manager Steve
 

References:
Wikipedia, The Shadow People by Jeffrey Palmer