Of course most of us are influenced by such horror films as Child's Play
. And most of the time even the spirits of Asian folklore seem bent or either destroying people or, at very least, playing very cruel tricks on man. Maybe somebody will give you a sound psychologial explanation.
But the aforementioned Japanese doll, again according to the monks, did nothing more than having growing hair: it didn't move, it didn't emit any sound, it wasn't associated with any other paranormal happening.
According to them it was left in their custody with other prized family heirlooms by a soldier leaving for China in the late '30s. When he came to claim his items after the war he opened the box together with a senior monk and they discovered the fact. Of course he left the doll in the temple for safekeeping and it has been there ever since. Of course we are not told if the former soldier has been given his share of the offerings...
To get back to the subject at hand we should open two very large parenthesis. The first one: is your doll possessed by an external spirit or did it develop one itself, like our Asian friends believe? The second one: we Europeans (but most monotheists as well) believe in possession being invariably the work of evil spirits. But travel among the shamanistic people of the Far East or the mysterious practicioner of Candomblé
and other African-Carib religions and you'll discover that sometimes possession by a spirit or deity, as fatiguing and dangerous as it is, is considered a gift or even a honour.
Now I have to get back to work or I'll be "possessed" too...