It seems that a popular belief is that poltergeist are the products of living people, most often adolescent girls. But, this research seems to
be contrary to that belief.
Try asking Asala about this...
Most cases of poltergeist activity do happen around young children, and in emotional stimuli... Numerous research studies back this up (as well as
personal experience). The only way they could get this to work for them, is to gain control of the child. However, as the child isn't consciously
directing it (but subconsciously), it's easier to cease the activity, than to try and control the subconscious....
This is not to say that there aren't entities capable of manifesting themselves enough to move things...but the accounts of such tend to be rare in
the extreme, without a small child present.