Dual Personality
What is popularly termed dual, split, or multiple personality
is one form of what psychologists call disassociation. Two or
more mental process in the individual can be said to be disassociated
if they either coexist or alternate without apparently influencing
one another or becoming connected. In the nineteenth
century, disassociation described a host of phenomena
from dreams to neurotic symptoms. Neurosis was explained as
a constitutional weakness in the person that prevented their integrating
their personality. Thus daydreaming was condemmed
as a symptom of nonintegration. A more extreme example
would be what had previously been called spirit possession.
When Freud proposed the existence of an underlying unconscious,
the idea of an underlying constitutional weakness
was abandoned in favor of a discussion of various mechanisms
by which the ego, the central waking personality, suppressed or
isolated unwanted elements and kept them out of the ongoing
ego formation.
However, Freudian categories do not handle well the most
extreme of disassociation phenomena characterized by the subject
maintaining for an extended length of time some action
not apparently initiated by the conscious self and the memory
of which is not available to the conscious self. Such phenomena
includes forms of amnesia, sleepwalking, and post-hypnotic
suggestions. It would also include the trance phenomena of a
Spiritualist medium or someone engaged in channeling, and
the now well-known phenomena of multiple personality, in
which the person appears to change from one person to another.
This last phenomena challenges some basic assumptions
about self identity, that each individual is just that, a single person
with a single memory, a more or less unified being.
Sometimes, in trance state, there occurs a split so pronounced
that the subject seems to have two or more distinct
personalities. The secondary personality may differ from the
primary in many ways, and possess entirely distinct intellectual
and moral characteristics. The entranced subject may allude to
his normal consciousness in the third person, may criticize its
opinions and attitude, or even express direct antagonism towards
This secondary personality sometimes alternates with the
primary in such a way as to suggest that two spirits are struggling
to possess the same physical organization. (For an example,
see William Sharp.) Another peculiarity of this state is that
whereas the normal consciousness generally knows nothing of
the others, the secondary personalities usually have full knowledge
of each other and of the normal consciousness.
The more extreme disassociation is by no means confined
to the trance state, but may arise spontaneously. Robert Louis
Stevenson made effective use of the philosophical implications
of dual personality in his science fiction horror story The
Strange Case of Dr. Jekyll and Mr. Hyde (1886). In a less horrendous
setting, it became familiar to many through the book and
movie The Three Faces of Eve. Sometimes the appearance of a
dual personality leads to other multiple personalities. In the famous
case of Sally Beauchamp, investigated by Morton Prince,
four well-defined personalities developed, as described in
Prince’s book Dissociation of a Personality (1905).
In many cases the emergence of secondary personalities is
due to a patient’s response to his or her counselor, an attempt
to fulfill a real or imagined request.
While much work and discussion has been done on the dysfunctional
multiple personality as a disassociation disorder, little
effort has been put into understanding mediumship and
channeling in the same way. Mediumship differs significantly
from multiple personality both in the control of the medium
over the appearance of the secondary personality and its nonpathological
Prince, Morton. The Disassociation of a Personality. 1905. Reprint,
Oxford Oxford University Press, 1978.