In dissociative identity disorder, each alternate personality "may be experienced as if it has a distinct personal history, self-image, and identity, including a separate name" (American Psychiatric Association, 2000, p. 526). Indeed as we shall see in the following example, the manifested personalities could perhaps more appropriately be characterized as caricatures of personalities.
The following are among the "more than 29 personalities" (Reich, 1989b, p. A6) as experienced by a woman named Brenda. Christina, age 34, "wears glasses, has short curly, auburn hair and greenish eyes." She "talks in a low voice, is very serious, and does not smile." Her purpose in Brenda's psychological makeup is to deal "with anger by expressing feelings verbally." Janice, age 16, has "shoulder length auburn hair, green eyes, slim build and dresses casually." She "speaks with a strong foreign accent from the years Brenda lived overseas and laughs about the destruction she causes." She is an alcoholic with an attraction for bars and casual sex. Her purpose is to express "anger by misbehaving and emotionally hurting others." Cindy is 19, attractive, thin, with shoulder length brown hair. She is "quiet, somewhat shy, and talks in a near whisper." She is "still coming to grips with being a teenager because she has recently grown from 11 to 19 with the help of a therapist." Her purpose is to deal with intimate problems.
Brenda also has childlike personalities. Liza, three and a half, is short and heavy with freckles and long pigtails. She "speaks in a child-like voice, slurring her words, talking slowly." Her purpose is to "act like a normal child." Penny, age 6, has long, blond, curly hair. She has "dyslexia, which causes her to print backwards." Her purpose is to bear the pain when Brenda is being harmed.
Different alternate personalities can hold down different jobs until they start interfering with one another. In Brenda's case, "Marion was working as a home renovator when Ronald emerged one day and put a holy through the drywall with a hammer." In addition to Marion having been a home renovator, Gillian had been a gourmet chef in a hotel, Christina has been a commercial artist, and Margaret and Mary had real estate licenses and has been successful real estate agents. The income from these jobs has been "deposited in bank accounts in the name of the personality who held the job, so that Brenda did not know she had saved this money or where to find it" (Reich, 1989b, p. A7).
The process by which control of the body passes from one personality to another is called switching (Hurley, 1985c, p.3) and usually occurs in one or two seconds. Switching can be voluntary or involuntary and can occur in response to a person's physiological or psychological condition or environment. As we have seen, switching can happen at inopportune times. Brenda has found herself "in a strange place with a strange man" after Janice had picked him up. In another case, "during surgery in a London hospital, a frightened personality emerged wide awake on an operating room table while the host was under anesthesia."
Physiological changes can accompany switching between personalities with apparent insensitivity to anesthesia being among the most dramatic. There can be "differences in visual acuity, pain tolerance, symptoms of asthma, sensitivity to allergens, and response of blood glucose to insulin." For example, allergies to animals such as cats can disappear with a change to a personality that is apparently not allergic to them. In one study, more than one third of clinicians reported having seen changes of handedness, half of their clients were reported to have alternate personalities that responded differently to the same medication, three quarters of the clients had alternate personalities with different physical symptoms, and one quarter had alternate-personality specific allergies. (Putnam, 1984, p. 32) Sometimes there are dermatological reactions that are specific to alternate personalities. For example, a woman who had had lighted cigarettes put out on her skin would manifest burn marks that would last for 6 to 10 hours when "the personality that received the burns took over during therapy sessions." Due to the rapid changes in physiology that sometimes accompany changes in personality, it is not surprising that people with DID sometimes "heal more quickly than other people" (Hurley, 1985d, p. 20).