Why would anyone think multiple personality is rare? [originally posted 2014]

Since all humans are members of the same species, most things that are found in any one person are also found in many other people.

Conditions are rarely diagnosed for three reasons:

1. Rare genetic disorders

2. Special Situations: including infections, weather, diet, toxins, radiation, trauma, culture, and fads.

3. Diagnostic ignorance

Most skeptics do not claim that multiple personality does not exist. They admit that there have been valid cases. All they claim is that valid cases are rare, because, they say, it is a culturally-bound phenomenon and a recent fad.

But the fact is that multiple personality and other dissociative conditions are not culture-bound. They occur all over the world (1).

Is multiple personality a recent fad or a modern artifact? Well, “demon possession” has been reported since biblical times. So if you think that multiple personality is a recent fad, you have to believe in demons.

Then, if multiple personality is neither a rare genetic disease nor culture-bound nor a recent invention, is its alleged rarity a matter of diagnostic ignorance? Who are these skeptics who allege that multiple personality is rare? Not the American Psychiatric Association, whose diagnostic manual, DSM-5, says that the prevalence of multiple personality disorder (called “dissociative identity disorder”) is greater than the prevalence of schizophrenia.

Then who are these skeptics? They are people who, if you ask them, will admit that they, themselves, have never made the initial diagnosis of even one of those allegedly rare, but valid, cases. They are people who—no matter how otherwise brilliant or expert—have never demonstrated diagnostic expertise in regard to multiple personality.

Do you need diagnostic expertise? Is multiple personality the only disorder in the diagnostic manual that is relatively common, but rarely diagnosed? Another example is body dysmorphic disorder. The diagnosis is usually missed, because, like multiple personality, people who have it rarely volunteer their symptoms.

I have addressed skepticism about multiple personality before, and made other points—regarding normal childhood psychology; how the symptoms are usually camouflaged and kept secret; and how the Freudian model of the mind tricks people into thinking that multiple personality is logically impossible—but I think it is worthwhile to revisit skepticism from time to time, because prejudice against multiple personality is so common, and the skeptics think that they are so enlightened and clever.

1. George F. Rhoades Jr PhD and Vedat Sar MD (Editors). Trauma and Dissociation in a Cross-Cultural Perspective: Not Just a North American Phenomenon. New York, Haworth Press, 2005.