Poltergeists, their name derived from the German poltern (to knock) and geist (spirits), are generally defined as mischievous and sometimes malevolent spirits. Reports of poltergeist activity typically feature raps, bumps, thumps, knocks, footsteps, and bed shaking, all without a discernible point of origin or physical reason for occurrence. Many accounts also report objects being thrown about the room, rains of dirt or other small objects, vile smells, furniture being moved, and even people being levitated or assaulted. Historically, poltergeist activity was ascribed to the devil, demons, or witches; such activity has also been suggested to be an unconscious use of psychokinetic abilities. Although skeptics argue that all such phenomena can be explained through physical mechanisms, or fraud, many continue to believe in spiritual or parapsychological causes.

Characteristics of poltergeists

The most commonly reported type of poltergeist activity is generally a combination of loud, unexplainable noises and the movement of objects. Objects can include everything from rocks to household appliances. Movement can occur on a small scale, or may involve the moving of large, heavy objects or the violent hurling of smaller ones. Electrical disturbances, such as the turning on or off of appliances or lighting, can also occur. In some extreme cases, poltergeists have been reported as violently attacking their victims, including sexual assault.
Poltergeists are classified according to have five levels of activity:
Level 1 , called "Senses Attack," involves cold spots, strange noises, and a feeling that one is being watched. Pets may behave strangely, and odd smells or offensive odors may be noticed.
Level 2 , called "Communication," is an increase in activity over Level One. Noises become more definable, turning into whispers, shrieking, moans, or giggles. Cold spots become cold rushes of air, small objects are thrown, and small marks may appear on walls.
Level 3 , called "Electrical Control," involves the turning on and off of appliances, disturbances happen with telephones, and windows and doors open and close and lock and unlock. Unseen hands may grab or touch people, and furniture may move.
Level 4 , known as "The Trickster Stage," is even more violent. Objects disappear or move violently, and sometimes burst into flame. Apparitions and voices appear, violently threatening people with foul language. People feel dizzy or nauseous, and may be physically attacked.
Level 5 is known as the "Danger Level," and is the highest energy level. Biting, scratching, punching, and even sexual assaults may occur. Kitchen knives or other deadly weapons are aimed at people, and blood may appear on the walls, floors, or ceilings. Where previous activity was frightening, level five activity is actually life-threatening.

Poltergeists are said to cycle through the above levels, which may take days, months, or even years. After level five, the poltergeist is said to go into a kind of dormancy, until eventually activity begins again with Level One.
Poltergeist activity is usually considered to be temporary, sometimes lasting as little as a day or two. Unlike ghosts, poltergeist activity is usually centered around an individual, not a place, and is generally more destructive.evil, demons, and spirits
Poltergeist activity was commonly thought to be the work of devils or witches. An account from the late 1600s describes a "Stone-Throwing Devil," or "Lithobolia," that plagued a New Hampshire family. Objects both inside and outside the home were moved, rocks were thrown violently about, and the family members were personally attacked. An elderly neighbor was said to be suspected of witchcraft.[8] Particularly in superstitious times and/or cultures, witchcraft and demons were blamed for most poltergeist activity, as well as instances of crop failure or sickness.
The idea of poltergeists as demons, however, is still present in much of Christian theological thought; some Christians believe that, since human dead are either in heaven or hell, and unable to roam the earth in the afterlife, poltergeist activity must be the work of demons. Proponents of this theory argue that poltergeist activity has strong evidence of a conscious intelligence, and that the nature of poltergeist attacks is often annoying, malicious, and sometimes viciously dangerous, and is intended to confuse, bewilder, and frighten victims.

Individual entities:

Some believe poltergeists may be the confused, lost, or angry spirits of the dead, unable to move beyond the "earthly plane." One version of this belief posits that poltergeists originate after a person dies in a powerful rage. Another theory postulates that ghosts and poltergeists are nothing more than "recordings" from persons no longer present. When there is a powerful emotion, in death or life, a recording of such an energy is then "embedded" in a place, or in the "fabric of time" itself. This recording will continue to play over and over again until the energy embedded disperses. Others believe poltergeists simply exist, like the "elementals" described by occultists.
Some poltergeists have seemingly had distinct personalities and the ability to articulate themselves, which suggests some sort of self-awareness and intent. Practitioners of astral projection, such as author Robert Bruce, categorize a number of beings that exist on the astral plane, and report the existence of unfriendly astral life forms, called "negs," who have the ability to harm as well as cause objects to move during psychic attacks.

Poltergeist agents:

The observation that poltergeist activity often occurs around an "agent," or a person that seems to act as a magnet for the activity, has led to the idea that the agent may well be the one responsible for the activity. Many parapsychologists believe that poltergeists are really unconscious psychokinesis, or PK. The term "RSPK," or "Recurrent Spontaneous Psychokinesis" is used to describe such a phenomenon. Agents are most often young; many are pre-pubescent. In the 1960s, researchers at the Psychical Research Foundation in Durham, North Carolina, studied 116 written reports of poltergeist activity, and came to the conclusion that children and teenagers used subconscious psychokinetic (PK) abilities to express hostility without fear of punishment. Children were not aware that they were causing the disturbances, but were generally pleased that they occurred. Interestingly enough, poltergeist activity can stop once the child goes through puberty, as in the case of Eleonore Zugan.
In the case of the Miami Poltergeist, poltergeist activity only took place when the disgruntled employee Julio Vasquez was present. A Cuban refugee, Vasquez was unhappy in his job, was often depressed and angry, and had recently attempted suicide. On days Vasquez did not work, all was calm, but when he was present, and particularly if he was experiencing strong negative emotions, the poltergeist activity was frequent. This suggests that the mental state of the agent can influence or create poltergeist activity.
Spontaneous PK is often the result of stress or emotional disturbances. Activity often centers around adolescents, as adolescence is a stressful and emotionally trying time of life. In many poltergeist cases, there are particularly strong mental issues in an agent, such as the case of the Macomb Poltergeist in 1948, where a teenager named Wanet McNeil moved with her father to Macomb, Illinois, after her parents had gone through a bitter divorce. Wanet was unhappy with the situation, did not like the farm, and wanted to see her mother. Small fires began breaking out on the walls and ceiling, igniting the curtains in each room, and engulfing a bed. Fire investigators found no flammable compounds in the wall and were mystified. Over 200 more fires broke out, eventually burning the house to the ground. Fires continued in surrounding structures. The events were later explained through a confession by Wanet that she had started the fires with kitchen matches, even though brown spots that soon burst into flame were observed by many people when Wanet was nowhere nearby. The girl went to live with her grandmother, but her emotional issues apparently continued as she grew older; later in life she was jailed for petty theft and prostitution.
Other teenagers who experienced poltergeist activity and entered therapy resolved their issues, ceased to be troubled by paranormal activity, and went on to live happy, fulfilled lives.

Caused by physical forces:

Some scientists have proposed that poltergeist activity has a physical explanation. Ionizing radiation, geomagnetic activity, static electricity, and electromagnetic fields can all affect the physical environment. Researchers use photography, temperature recording equipment, tape recorders, and other electronic equipment to investigate alleged paranormal phenomena. Seismic activity and meteorological conditions are also taken into account, along with other natural activity like subterranean water movement, in order to determine a natural and scientific cause for poltergeist-like activity. Sophisticated arrays of sensors are used to obtain the most accurate data surrounding poltergeist activity.
John Hutchinson claimed that he created poltergeist effects in the laboratory, using a variety of sources of electromagnetism. Hutchinson claims to have levitated objects, started spontaneous fires, distorted metal, swirled water inside containers, broken mirrors from 80 feet away, and made metal white-hot without burning any surrounding materials, all using equipment hooked up to a standard residential electrical supply.
Naturally, science has not been able to explain all poltergeist phenomena. While proponents of a paranormal explanation view this as evidence supporting poltergeist activity as paranormal, those who support the physical causes theory tend to believe that science will likely be able to someday explain them.

THEORIES :

Historically, poltergeists were often thought to be manifestations of the devil or demons, or the work of witches and sorcery. Modern research tends to put poltergeist activity into several main categories: Individual entities (either malicious or simply mischievous), unconscious psychokinetic activity, and physical explanations (such as electromagnetic forces). Additionally, some purported poltergeist activity is nothing more than fraud.