Multiple Personality


Multiple personality disorder (MPD), now known as dissociative identity disorder (DID), is defined by the DSM-III (so many abbreviations, aah!) as a dissociative disorder in which two or more distinct personalities exist together within one individual. This is a neurotic disorder.

Thigpen and Cleckley, two American psychiatrists, studied a woman who was suffering from various problems. They investigated her case which actually ended up as a famous case study that was even made into a movie!

Corbett Thigpen                                                                                                             Hervey Cleckley

This was a case study which means it was focused on one individual: a 25-year-old woman known as “Eve White”.

Eve White

Thigpen and Cleckley met Eve when she was referred to them due to her “severe and blinding headaches” and “blackouts”. The psychiatrists’ first assumption was that Eve was suffering from common frustrations, stress and marital problems. However, the real issue slowly began to reveal itself.

The psychiatrists conducted a number of interviews with the patient and her family, and they used various other methods: observation, hypnosis, EEG tests, psychometric measures (e.g. an IQ test) and projective tests (an ink-blot test).

Eve was interviewed a few times and nothing extraordinarily problematic was revealed. However, the psychiatrists were not sure why Eve was unable to remember a recent trip she had taken. They used hypnosis to successfully clear her amnesia. Some weeks after, a letter from Eve was sent to the psychiatrists’ office. It was about her therapy sessions and was written in her normal handwriting but, at the bottom of the page, there was a paragraph written in child-like handwriting. When Eve was asked about it, she recalled beginning a letter in the same way but denied writing the bottom part.

The letter

During this interview with the letter, Eve lost her controlled persona and became agitated. She seemed distressed and asked the psychiatrists if hearing an occasional imaginary voice made her insane. She explained that she had heard a voice addressing her on several recent occasions. As this conversation continued, Eve suddenly put both hands to her head as if she was in pain. After a moment of silence, she dropped her hands and brightly said, “Hi there, Doc!” with what the therapists observed as a “quick, reckless smile”, much unlike the ordinary and meek Eve White.

Eve had changed into a carefree, confident woman. Her physical presence was more upfront and direct, and the psychiatrists noted that this new persona had “a childish daredevil air, an erotically mischievous glance, a face marvellously free from the habitual signs of care, seriousness and underlying distress.” When they asked about her name, she immediately replied that she was Eve Black.

Eve Black

Thigpen and Cleckley observed that although Eve Black would show up spontaneously, they could only call her out when Eve White was under hypnosis. The psychiatrists were also able to request Eve Black to let them speak to Eve White. After several sessions, hypnosis was no longer needed to swap between personalities. However, this obviously complicated things because now Eve Black could take over from Eve White more easily.

It was believed that Eve Black had enjoyed living an independent life since Eve White’s early childhood. Eve Black recalled many childhood incidents in which she was naughty or disobedient but for which Eve White was later punished. Some of these incidents were supported by information from Eve White’s parents and husband in other interviews. For example: Eve White had to face her husband’s temper when he found a hoard of expensive clothes hidden in her drawer, supposedly bought on a shopping spree which Eve Black later confessed to.

Thigpen and Cleckley stated that Eve Black’s behaviour was “characterised by irresponsibility and a shallowly hedonistic desire for excitement and pleasure.” She succeeded in hiding herself from Eve White herself, her parents and her husband. She also denied being married to the husband, who she strongly disliked, and denied any relationship with Eve White’s young daughter. To the husband, daughter and parents of Eve White, unexpected acts of unpleasant behaviour, harshness and occasional violence were interpreted as “unaccountable fits of temper in a woman who was habitually gentle and considerate.”

During the longer periods where Eve Black was present, she avoided the family and close friends, instead seeking the company of strangers. She also kept her real identity secret by imitating Eve White when necessary.

The tests given to Eve White and Eve Black also gave further insight into the differences between these two personalities:

IQ test results:
Eve White: 110
Eve Black: 104

Memory test results:
Eve White’s memory was much better than Eve Black’s memory.

Rorschach test and drawing-human-figures test:
Eve Black’s personality was deemed to be much healthier than Eve White. Eve Black was regressive while Eve White was repressive and showed many obsessive-compulsive traits, rigidity and an incapability to deal with hostility.

It was clear that Eve Black did not sympathise with Eve White and could not be persuaded to help her during therapy sessions. It was noted that Eve Black “often misled the therapist into believing she was cooperating, when in fact her behaviour was particularly detrimental to Eve White’s progress.” As Eve White became aware of Eve Black’s existence, she slowly became capable of preventing her from coming out. This meant negotiations were needed for Eve Black to have more time ‘outside’.

After eight months of treatment, Eve White was making progress. Her blackouts reduced, she was working to solve her marital problems and she had a steady job as a telephone operator. However, as the treatment continued, Eve White’s headaches and blackouts returned. Eve Black said she was not responsible and that she was also experiencing a lack of awareness during the blackouts. Eve White’s state of mind was deteriorating. It became easier for the therapists to call on either personality and childhood experiences were again investigated under hypnosis. During one of these sessions, Eve White appeared to relax sleepily. After two minutes, her eyes opened blankly and she stared around the room and looked at the therapist. She then said in an unfamiliar, husky voice: “Who are you?”

Thigpen and Cleckley concluded that another personality – who called herself Jane – had emerged. They discussed that Jane was more responsible than Eve Black and more confident and interesting than Eve White.


After Jane’s appearance, all three personalities were given EEG (electro-ence-phalo-gram) tests. A clear distinction was visible between the readings of Eve Black and the two other personalities. However, it was not possible to make a clear distinction between Eve White and Jane’s EEG readings.

After several months of working with all three personalities, the therapists concluded that if Jane took control over the other personalities, the patient would gain full health and attain a happy life. Jane had awareness of both Eves’ thoughts and behaviours, but she did not have access to their memories prior to her appearance. Jane learned to take over many of Eve White’s household tasks and helped her. She also showed compassion towards Eve White’s daughter. However, although the therapists were able to work with Jane to determine if Eve Black was lying about something, it was not possible for Jane to displace Eve Black or to communicate through her.

Thigpen and Cleckley decided that bringing Jane forward was the way to help the patient’s troubled mind and they agreed that her dominance would be an appropriate solution. Needless to say, a lot of ethical issues and morality debates come into play here.

The woman known here as Eve White/Eve Black/Jane came into the public eye in 1975 and named herself as Christine Costner Sizemore.

The real ‘Eve’ in 2008

She claimed that she had experienced many other personalities before and after therapy, and she suggested a total personality count of 22. She also published a book about her experiences in 1977. It was suggested that Christine’s personalities appeared as a defense mechanism to protect her mind from things it was unable to cope with. For example, as a very young child, Christine witnessed two deaths and a traumatising accident.

Type of research method
This was a case study. That means there was no independent variable or dependent variable; this is simply an in-depth analysis on an individual.


  1. In-depth data:This was a case study, meaning that it focused on one individual. Such an investigation results in a large amount of detailed information on the topic, in this case: multiple personality disorder. The data collected on this disorder could have been really helpful back in 1950, an era where such personality disorders were rarely diagnosed and mostly unknown.


  1. Not generalisable:Since this was based on one individual, a young woman from America, there is no way we can generalise other people under the findings of this study. Individual differences act as a barrier to generalisation in case studies.
  2. Demand characteristics: Eve may have kept certain information, such as her feelings or experiences, private in front of the therapists. People may do this to look socially desirable or “normal”.
  3. Researcher bias:The majority of conclusions made by Thigpen and Cleckley were based on subjective views. There was no measurable or observable cause-and-effect relationship to be identified, it was all based on the psychiatrists’ interpretations of Eve.
  4. Not replicable:This case study cannot be replicated as it was based on one person and her individual life experiences, feelings and behaviour. This means the reliability of the results cannot be checked.

Ethical issues

  1. Informed consent:There was informed consent; Eve had given permission for the study to continue.
  2. Deception: There was no deception.
  3. Confidentiality: Although at first Eve’s real identity was kept confidential, she eventually came into the public eye and identified herself. This was, however, her own choice and the psychiatrists had respected her privacy. On the other hand, after Eve revealed her real identity and her story became known, she claimed that she was unaware of Thigpen filming some of the therapy sessions. Thigpen and Cleckley wrote a book about Eve and sold the rights, eventually resulting in a movie about this case. This can be seen as a violation of privacy because Eve had not given permission for cameras to be used during therapy sessions.
  4. Emotional or physical harm:There was no physical harm, but the emotional aspect is pretty debatable here. Could the psychiatrists have harmed Eve’s emotional stability through the use of hypnosis? Could they have had an effect on her emotions when they declared Jane as the ‘most appropriate’ personality for a stable, happy life? Although Eve did not complain of the therapists emotionally harming her, their part in this study has raised a lot of questions about the result on Eve’s mental health.
  5. The right to withdraw:Eve could have left the study at any time and discontinued treatment because she had the right to withdraw; she was not forced to get checked or forced to continue treatment.
  6. Debriefing: There was not a real necessity for debriefing in this case study.

Reference: Thigpen, C. H. and Cleckley, H. (1954). A Case of Multiple Personality. Journal of Abnormal and Social Psychology.