To the extent that generalizations can be made, people with BID appear to start to wish for amputation when they are young, between eight and twelve years of age, and often knew a person with an amputated limb when they were children; however, people with BID tend to seek treatment only when they are much older. People with BID seem to be predominantly male, and while there is no evidence that sexual preference is relevant, there does seem to be a correlation with BID and a person having a paraphilia; there appears to be a weak correlation with personality disorders. Family psychiatric history does not appear to be relevant, and there does not appear to be any strong correlation with the site of the limb or limbs that the person wishes they did not have, nor with any past trauma to the undesired limb.