Dear Cecil: My wife and I are having a disagreement on whether multiple personality disorder is real or not. She works in a substance abuse clinic and says she sees people with this disorder quite often. I on the other hand feel that multiple personality disorder is a crock of dung. I have looked this up on the Internet, and views seem to be split fifty-fifty. What do you think — does this disorder exist? Mark, via the Internet

Cecil replies:

Your columnist doubts it. Your columnist doubts everything. But in this case he’s got a lot of company. Multiple personality disorder, now officially known as dissociative identity disorder (DID), remains the object of bitter controversy. One thing’s clear, though — it’s not nearly as common as people thought just a few years ago.

Possible cases of split personality have been reported in the medical literature since the early 19th century, and the condition was formally defined in the first years of the 20th. But until recently it was considered extremely rare — fewer than 200 cases were described before 1980. The diagnosis became much more common in the 80s for several reasons. One was the phenomenal popularity of Flora Schreiber’s 1973 book Sybil, which told of a woman with 16 personalities. Stories of “multiples,” fictionalized or otherwise, were nothing new — The Three Faces of Eve dates from 1954, “The Strange Case of Dr. Jekyll and Mr. Hyde” from way back in 1886 — but Sybil made a crucial innovation, introducing the idea that multiple personalities stemmed from trauma during early childhood. Around the same time, child protection advocates and feminists began arguing that child abuse, especially sexual abuse, occurred far more often than previously supposed. And in the late 70s, in a phenomenon thought to be linked to the resurgence of Christian fundamentalism, reports of so-called satanic ritual abuse first captured the public’s imagination.

Presented with, on one hand, allegations of an unrecognized epidemic of crimes against innocents and, on the other, a simple mechanism to explain why their troubled patients couldn’t remember any abuse (i.e., the personality divides in order to shield itself from horrific memories), a small but devoted group of therapists began diagnosing multiple personality disorder with alarming frequency — more than 20,000 cases had been reported by 1990. Under the influence of hypnosis and other techniques, subjects reported dozens, hundreds, or even thousands of “alters” whose behavior, age, sex, language, and occasionally species differed from that of their everyday personas. Alters were coaxed into revealing bloodcurdling stories of abuse by family members, or of sacrificing their own babies to shadowy cults. One prominent multiple personality specialist claimed that the satanic network programmed alters into its victims, which it could then trigger to act in certain ways by sending them color-coded flowers.

By the early 1990s it began to dawn on rational folk just how preposterous the whole business was. Having investigated more than 12,000 accusations over four years, researchers at the University of California, Davis, and the University of Illinois at Chicago determined that not a single case of satanic ritual abuse had been substantiated. A 1992 FBI study arrived at the same conclusion: overeager therapists had planted horror stories in the minds of their patients. In 1998 psychologist Robert Rieber made a convincing case, based on an analysis of audiotapes, that even the famous Sybil had confabulated her multiple personalities at the insistence of her therapist. The bubble burst, and diagnoses of multiple personalities subsided.

OK, so it was all a case of mass hysteria. The question remains: Are multiple personalities ever real? The debate still rages. Skeptics claim that alters are invariably induced by the therapist; the more respectable defenders of DID agree that many are, but not all. The controversy has been complicated by disagreement over the nature of personality. The common understanding of DID is that the alters are independent of one another and don’t share memories and other cognitive processes, but demonstrating this has proven difficult. Speech and behavior are under conscious control, so changes can readily be faked. Even things like brain-wave patterns may vary not because of a genuine personality switch but because alleged alters cultivate different emotional states and different ways of acting out. In a recent study of several DID patients, successive alters were asked to memorize different sets of words. When alter B was asked whether she recognized a word memorized only by alter A, she often hesitated. That suggests a conscious process — I’m not supposed to know this — indicating the personalities aren’t truly independent.

Research continues, but my feeling is this. Assuming that the diagnoses of the past 25 years were trumped-up and that the couple hundred cases reported between 1800 and 1979 represent the true incidence of the syndrome, we’re talking about maybe one or two cases per year. If DID is as rare as all that, what’s the big deal?

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.