One study of the motives of Necrophiliacs showed that:

        68% were motivated by a desire for an unresisting and unrejecting partner;
        21% by a want for reunion with a lost partner;
        15% by sexual attraction to dead people;
        15% by a desire for comfort or to overcome feelings of isolation; and
        11% by a desire to remedy low self-esteem by expressing power over a corpse

    (Roman and Resnick, 1989)