The personalities are usually almost exact opposites in character unaware of the other personality. Each one usually has its own name, distinct traits, moods, independent relationships and memories. The personalities may even have different ages, sexes, or races. Some multiple personalities will change their person according to the time of day. This disorder usually begins in early childhood.
Psychologists believe it is a coping mechanism to escape problems of abuse or memories of abuse.
Many people do not know they have more than one personality until adulthood. People usually figure it out because of erratic behavior or blank periods of time in their memory. Symptoms of a multiple personality are extremely hard to determine. Many times a multiple personality will have long, blank, empty, unexplainable time in memory. Of course, the obvious symptoms would be having or becoming another totally different person at different times of day routinely.