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A Life With Others…In Your Head?

By Stepheni Uh

Undergraduate Neuroscience and Behavioral Biology Major

Emory University

This post was written as part of the Contemporary Issues in Neuroethics Course

Although decades have passed since the world first heard
of Billy
, his predicament and story still cause confusion and wonder. As
the field of neuroscience is expanding, more light has been shed upon his
condition: an extreme case of dissociative identity disorder (DID), formerly
known as multiple personality disorder. Advancements in neuroscience (i.e. in
research techniques) has led to the investigation of possible neurobiological
correlations to the symptoms of DID – yet, due to the rare cases of this
disorder, the possible neurobiological basis for DID has not been established.
Despite the lack of raw data, per se, neuroscience has fueled new perspectives
regarding the nature of DID such as those involving the ideas of culpability,
personhood, and individuality.

Billy Milligan

Billy Milligan, whose birth name is William
Stanley Milligan, had approximately 24 different personalities that fought to
take over his body – Arthur the intelligent Englishman; Philip the Brooklyn
criminal; David the eight-year-old “keeper of pain”; Adalana the lesbian and
everyone else, including the Teacher who could fuse all of the personalities and
help them develop [1,4]. Milligan was involved in robberies and other crimes
before he was prosecuted for kidnapping and raping three women from the Ohio
State University campus in October 1977 [4]. According to his psychiatric
report, Adalana had taken over Milligan and consequently raped the women due to
her desire for affection. The other personalities, however, had no recollection
of the incident [4]. Billy Milligan was eventually acquitted of his crimes by
reason of insanity and sent to the Athens Mental Health Center to “recover.”
Experts attempted to treat him by fusing all the personalities into one, which
was already established by the Teacher; so they attempted to make the Teacher
take over his “consciousness,” which had never happened before. Milligan was
finally released in 1988 and then became free from supervision in 1991 [4]. As
of today, no one knows what has happened to Billy Milligan and many questions
remain unanswered.

According to the DSM-IV, DID is a “dissociative disorder” in
which individuals with DID present two or more distinct personalities that
repeatedly affect the individual’s behavior [3]. Dissociative disorders are
ones that involve significant “…disturbances in memory, identity,
consciousness, and/or perception of the external environment” [3]. In the case
of a DID patient, his or her personalities may show evident differences in
handwriting, voice, and even physical characteristics [3]. Another interesting
aspect of this disorder is that many times dissociative amnesia is present for
these individuals. Dissociative amnesia refers to the process of separating
events or memories from one’s “stream of consciousness” due to the overwhelming
stress that the event caused [5]. Often times for DID individuals, the behavior
of one personality or alter are not recalled by the other alters [5]. In Billy
Milligan’s case, therefore, it could be that when he became Adalana, the other
personalities did not recall her actions due to the extremity of the crimes.

The causes of DID are controversial and still
not agreed upon. Some psychotherapists, psychologists, and researchers believe
that the core features of DID are a result from various social conventions such
as therapists (who may cause the release or creation of more personalities by
questioning the individual whether other personalities exist), media
influences, as well as stigmatization of the disorder itself [3]. Others,
meanwhile, advocate the idea that severe and traumatic experiences such as
physical and sexual abuses during early childhood result in the dissociating of
personalities as a means to cope with their pain, which then causes DID [3, 4].
The neurobiological basis of DID is also unclear, but one study found that DID
individuals had smaller hippocampal and amygdalar volumes than healthy
individuals [6]. Information and research on DID are lacking because of the
small number of reported cases of DID, which could be due to either the rarity
of the disorder or the difficulty of diagnosing the disorder itself. Thus, many
dilemmas are present – particularly in the legal setting – when dealing with
people who claim to have multiple personalities.

Several challenging and controversial ethical
issues arise from the existence and characterizations of this disorder: determining
the level of responsibility DID individuals hold over their actions; if criminals with DID are competent
to stand trial and whether multiple personalities should
be treated as multiple people. Due to the lack of knowledge concerning the
basis and origins of DID, it is difficult to come up with any conclusions to
the aforementioned issues. The first issue revolves around the extent of
control DID individuals have over their actions as well as their intents. In
particular, the ways in which alters take turns (not necessarily equally) to
take over an individual’s body are ambiguous. Second, the difficulty of
determining the level of competency for DID individuals to stand trial is underscored
by amnesia of behaviors committed by specific alters. The inability to recall
the actions of one alter by all other alters is unclear in terms of why and how
this occurs. If they cannot remember what one of their alters did, how can they
defend themselves [5]? It is possible, as mentioned before, that the criminal
actions of one alter were so extreme that the individual dissociated the memory
from all other alters. This postulation, however, then brings up the point of
whether or not the individual is aware of right versus wrong as well as the
ties to his/her consciousness. Another challenge is detecting if they are lying
about their amnesia, which could potentially be investigated through
brain-imaging techniques such as fMRI. The validity of brain imaging as a lie
detector, however, is still debated and further investigated by many

Finally, there is much controversy in whether or
not the multiple alters present in DID individuals are fully developed and
autonomous personalities. This issue ties into the dilemma of criminal
responsibility. In Billy Milligan’s case, Adalana is the one who committed the
rapes, so should she be tried independently with separate legal representation
from all the other alters? There actually have been some incidents where trial
judges have required all DID alters to be sworn in before providing testimony
[3]. Future neuroscience studies may be able to investigate whether there are
functional, or perhaps even structural, brain changes when a DID individual
becomes another alter. The data from this type of research could contribute to
the issue of determining whether these alters are autonomous and separate from
one another. Yet, this also raises the dilemma of defining “personhood”: can
the human brain be used as a marker for different persons? Determining the
criteria for personhood is a complex and philosophical issue that has yet to
reach a conclusion. There are many factors that have been tied to defining
personhood such as self-awareness, autonomy, and rationality, but neuroscience has
opened the possibility of defining a person by his or her brain. For a DID
individual, however, it seems that these alters have arisen from the various
experiences of the individual. Thus, the alters are still technically part of
one “person,” but simply represent the individual’s mental and emotional
capacities. As in the case of Billy Milligan, he still contains the Teacher,
which somehow encompassed all of his alters. In this case, they do not seem to
be completely separate and autonomous individuals – two key aspects that I believe are necessary to define a person or an individual. Whether
or not the brain can be used as a factor for distinguishing persons is also an
interesting area of study that remains quite controversial. If the brain is in
fact identified as a criterion for personhood, it would imply that the entity
of a person is correlated – or “reduced” – to the brain. This notion of course
is controversial and possibly impossible to ever solve.

DID exemplifies one of the most complex and
controversial psychiatric disorders. How and why DID arises remain unanswered
and therefore create many problems in determining how to treat DID individuals.
The meanings and levels of responsibility, personality, and individuality are
all questioned by DID thus making one wonder if this is a disorder of the mind,
the brain, or perhaps both. Neuroscience can help provide more answers in terms
of the possible correlations between the brain and behavior of DID individuals.
Studies on the neurobiological aspects of DID patients can shed light onto
whether or not there are significant changes in the brain when transitioning
from one alter to the next. Determining the amount of control these individuals
have over their behaviors while they are in their certain alters, however, will
be an immense challenge. Thus, determining legal culpability of these
individuals will not be as black and white. As the field of neuroscience
continues to expand and progress, nevertheless, we may be able to define the
nature of personhood in individuals who display multiple personalities. Until
then, establishing the criteria for criminal culpability for and understanding
the disposition of people like Billy Milligan will remain challenges that
neuroscience may eventually help resolve.

[1] Wolpe and colleagues (2005)
discuss and analyze the discourse on fMRI as a valid lie detector and emphasize
the need for the ethical considerations of cognitive privacy, threats to civil
liberties by this type of research, and subjective interpretations of fMRI data. 


1.  Coles, R. (1981, November 15). Arthur, Ragen, Allen, et al. The New York Times. Retrieved from:

2.  Lewis, D. O., Yeager, C. A., Swica, Y., Pincus, J. H., & Lewis, M. (1997). Objective documentation of child abuse and dissociation in 12 murderers with dissociative identity disorder. The American Journal of Psychiatry 154(12):1703-1710. 

3.  Lilienfeld, S. O., & Lynn, S. J. (2003). Dissociative identity disorder: multiple personalities, multiple controversies. In Lilienfeld, Lyn, & Lohr (Eds.), Science and pseudoscience in clinicial psychology (pp. 109-142). New York: Guilford Press. 

4.  Maher, J. (2007, October 28). 30 years later, multiple-personality case still fascinates. The Columbus Dispatch. Retrieved from:

5.  Porter, S., Birt, A. R., Yuille, J. C., & Herve, H. F. (2001). Memory for murder: a  psychological perspective on dissociative amnesia in legal contexts. International Journal of Law and Psychiatry 24(1):23-42. 

6.  Vermetten, E., Schmahl, C., Lindner, S., Loewenstein, R. J., & Bremner, J. D. (2011). Hippocampal and amygdalar volumes in dissociative identity disorder. Am J Psychiatry 163(4):630-636.

7.  Wolpe, P. R., Foster, K., & Langleben, D. D. (2005). Emerging neurotechnologies for lie-detection: promises and perils. American Journal of Bioethics 5(2):39-49.

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