Certain tribes in Assam believe that head-hunting is necessary to produce a high birth rate and abundant crops. Collecting heads means to them collecting souls, and there must be a large stock of souls on hand to ensure reincarnation. The oval form of their villages and the sacred tree in the center are interpreted as representing the female genital and the phallus. A skull on the house represents a penis, the house itself the womb. The garden also signifies a woman and the new rice is looked upon as a newly born infant. The inhabitants of the same village regard themselves as persecuted by all outsiders thus passing on this idea to the younger generation. 'Paranoia might be a cropping up of the old racial memories of persecution by some distant people living in a hostile village.'