Poltergeists, in German meaning "noisy ghost", are a unique type of spirit that seek recognition and attention, and will do anything to receive it, even if they are violent and deadly methods. The best defining mark of a poltergeist is any manipulation of the physical environment, such as the movement of objects, physical attacks, spontaneous combustion, and so forth.
Much of the time, the Poltergeist phenomenon is incorrectly credited to mischievous spirits, ghosts or extremely negative entities. However, more modern scientific studies reveal convincing arguments that poltergeists are associated with psychokinesis, which is the ability to move objects and even people by power of the mind alone. This kinetic type of energy remains unexplained, but even some mainstream scientists are starting to explore the idea that it does exist.
A common factor of classic poltergeist activity is the presence of an adolescent, usually female, in the household or for all of the activity to be centered around one specific person. It's not uncommon for the activity to not take place unless that person is present at the time. In most cases, when that specific person is removed from the location, the events cease. A poltergeist is generally accepted to be the manifestation of one's extreme stress and anxiety. They are sometimes even attracted to places where beings of great evil (such as powerful demons) manifested.