Multiple Personality could not be surprisingly common unless childhood trauma and imaginary companions were surprisingly common: Are they?

How plausible is it that 1.5% of the general public has clinical multiple personality (according to the psychiatric diagnostic manual, DSM-5), and that upwards of 90% of novelists and up to 30% of the general public have a nonclinical version (suggested by my study of novelists)?

For that to be plausible, two preconditions would have to be surprisingly common: 1. a natural tendency for normal children to create alternate personalities, and 2. childhood trauma (to perpetuate and amplify the children’s natural tendency to create alternate personalities).

The natural tendency for normal children to create alternate personalities is shown by imaginary companions. So how common are imaginary companions? “If we consider all cases of imaginary companions created up to the age of 7, 63 percent of the children in our study had them” (1, p. 32).

That may seem like a high figure, but the researchers interviewed both children and parents—sometimes the children didn't remember that they had imaginary companions, but the parents did, and other times the parents hadn’t known about their children’s imaginary companions—and the researchers were aware of all the forms that imaginary companions can take.

How common is childhood trauma?

“Depending on how various traumatic experiences are defined, 8–12% of American youth have experienced at least one sexual assault; 9–19% have experienced physical abuse by a caregiver or physical assault; 38–70% have witnessed serious community violence; 1 in 10 has witnessed serious violence between caregivers; 1 in 5 has lost a family member or friend to homicide; 9% have experienced Internet-assisted victimization; and 20–25% have been exposed to a natural or man-made disaster” (2).

In short, since the two preconditions for multiple personality are relatively common, it is plausible that multiple personality is relatively common.

But if multiple personality is so common, why haven’t you seen it? Because, unless you’ve been reading this blog in its entirety, you probably don’t know what it looks like.

1. Marjorie Taylor. Imaginary Companions and the Children Who Create Them. New York, Oxford University Press, 1999.

2. Benjamin E. Saunders and Zachary W. Adams. “Epidemiology of Traumatic Experiences in Childhood.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3983688/