In the Showtime series United States of Tara, actress Toni Collette plays Tara Gregson, a Kansas mother who has dissociative identity disorder (DID), known formerly as multiple personality disorder. As with others with DID, Tara vacillates unpredictably between various personalities, often referred to as alters, over which she does not have control. One of these alters is a flirtatious and flamboyant teenager, another is a traditional 1950s housewife, and a third is a boisterous Vietnam War veteran.
Many films, such as The Three Faces of Eve (1957) and Me, Myself, and Irene (2000), similarly portray individuals as possessing more than one personality. Some of them even confuse DID with schizophrenia [see “Living with Schizophrenia,” by Scott O. Lilienfeld and Hal Arkowitz; Scientific American Mind, March/April 2010]. Even the revised fourth edition of the American Psychiatric Association’s diagnostic manual, published in 2000, specifies the core features of the disorder as the “presence of two or more distinct identities or personality states.” Yet despite the pervasive popular—and professional—portrayal of this disorder, research casts doubt on the idea that anyone truly harbors more than one personality.
Plenty of evidence supports the idea that DID is not merely a matter of faking and that most people with the condition are convinced that they possess one or more alters. Although a few DID patients have only one alter—the so-called split personality—most report having several. In a survey conducted in 1989 by psychiatrist Colin Ross, then at Charter Hospital of Dallas, and his colleagues, the average number of alters was 16. Interestingly, that is the same number of alters purportedly possessed by Shirley Ardell Mason, the woman known as Sybil in the 1973 best-selling book and two made-for-television movies that popularized the diagnosis of multiple personality disorder. (Later evidence emerged suggesting that Sybil’s primary therapist encouraged her to display multiple personalities, creating a huge sensation.) In rare cases, the number of alters may reach into the hundreds or even thousands.
Differences among alters can be nothing short of astonishing. Alters within the same patient may be of different ages, genders, races and even species, including lobsters, ducks and gorillas. There have even been reported alters of unicorns, Mr. Spock of Star Trek, God, the bride of Satan, and Madonna. Moreover, some practitioners claim that alters can be identified by objective characteristics, including distinct handwriting, voice patterns, eyeglass prescriptions and allergies. Proponents of the idea of multiple personalities have also performed controlled studies of biological differences among alters, revealing that they may differ in respiration rate, brain-wave patterns and skin conductance, the last being an accepted measure of arousal.
The question of whether people can harbor more than one character has important legal and therapeutic implications. If they can, and if patients are often unaware of their alters’ actions, a legal defense of “not guilty by virtue of DID” may be justifiable. Other scholars have argued that each alter is entitled to separate legal representation. As professor of law Ralph Slovenko of Wayne State University noted in 1999 in an article, some judges have even required each alter to be sworn in separately prior to testifying.
In treating these patients, many therapists try to get them to integrate their discrete personalities into a coherent whole. In doing so, they may help patients contact “undiscovered” alters and forge lines of communication among alters. For example, Ross has advocated naming alters and holding “inner board meetings” in which they can converse, share opinions and provide information about missing alters. Psychiatrist Frank Putnam of Cincinnati Children’s Hospital has argued for the use of DID “bulletin boards” on which alters can post messages for one another in notebooks or other convenient venues.