Clues that Presidential Candidates or Anyone Else might have Multiple Personality: Sincere Lies, Puzzling Inconsistency, Fanatical Consistency, Memory Gaps.

Clues that a person might have multiple personality are not the same as definitive evidence that a person has multiple personality.

At present, the only definitive evidence that a person has multiple personality is to meet and converse with the person’s alternate personalities (who honestly believe they are separate, distinct persons) and for at least one of these personalities to be unaware of, and have amnesia for, at least one of the other personalities; or to have the equivalent information from other reliable observers or documents; and for the evidence to be beyond reasonable doubt, since there are no other good medical or psychiatric explanations for it, and it occurred when there were no pending court cases or other reasons to fake.

Clues to multiple personality are important, however, because if you don’t know the clues, you will never look for the evidence, which is usually camouflaged, because the regular, “host” personality may be the one with amnesia for the other personalities, and the other personalities generally prefer to remain incognito, so that nobody will interfere with them.

Sincere lies—when you know the person is lying, but the person (actually, the host personality) believes they are telling the truth—are a clue. These lies happen because one personality claims not to have said or done something, you know the person did say it or do it, but you don’t know it was another personality who said or did it. Since multiple personality starts in childhood, some adults with multiple personality have had a reputation of being liars since childhood.

Puzzling inconsistency may be due to the different behavior, preferences, interests, abilities, etc., of different personalities, coming and going incognito. One euphemism for this is to say that a person compartmentalizes.

Fanatical consistency, the opposite extreme, can also be a clue, because alternate personalities, it must be remembered, are not whole, well-rounded persons. That is why the American Psychiatric Association coined the term “dissociative identity” (which suggests that there is only one pie, and that each personality is only one slice of that pie) to replace “multiple personality” (which suggests that there is more than one pie). Although each alternate personality can superficially come across like a whole person, they are really rather limited to certain emotions, abilities, interests, etc., and if you only know the person under circumstances in which that particular personality is out and in control, it might come across as a fanatical consistency.

Memory gaps (if the person will admit to having them, which is a big if) are a very good clue, because they raise the possibility that one personality has had amnesia for what another personality has said or done. People with multiple personality often have quite excellent memory, generally speaking, so their memory gaps are rather remarkable (if they admit them).

For example, Mark Twain had a reputation for an extraordinarily good memory, but also for remarkable episodes of “absent-mindedness.” Search Mark Twain in this blog to find a number of posts on him, including one on his absent-mindedness.

But, you may ask, isn’t multiple personality too rare to consider? Well, according to the American Psychiatric Association’s diagnostic manual, DSM-5, its prevalence is 1.5%, which would be more than four million Americans. And that is only for the mental illness, multiple personality disorder (also known as dissociative identity disorder).

I argue in this blog that there is a much more common, normal version of multiple personality, which has the alternate personalities and memory gaps, but lacks sufficient distress and dysfunction to make it a mental illness.

For certain purposes, like writing novels, a normal version of multiple personality is a positive advantage. Some alternate personalities have a great imagination, which is very real to them; indeed, as one novelist said, “more real than real.”

And it is an old joke among novelists that they are professional liars.