vi THE ANATOMY OF HUMAN PERSONALITY 231
answers to questions, whispered in his ear by one person, while carrying on a conversation with another person. Both his conversation and his written answers are sensible and meaningful. Apparently, two habit systems with little or no connection are functioning in the individual at one and the same time. In successive dissociation, the usual activities of the individual are suddenly broken off and replaced by a different mode of life. The individual frequently has no consciousness of his former self in his new personality role. Often he alternates between his two personalities. In such a dual personality, the individual has two major action systems so incompatible with one another that both cannot be given expression at the same time.
One of the first recorded cases of double personality is that of Mary Reynolds, mentioned by William James.112 Her friends and relatives knew Miss Reynolds as a reserved, timid, melancholy, even morbid creature. One morning she awoke with all memory of her previous existence gone. She even had to re-learn the acts of reading and writing. Her disposition, moreover, had completely changed. She was now fearless, buoyant and gregarious. After five weeks she lapsed back into her first personality with no knowledge of what had befallen her. These alterations from one state to another continued at intervals of varying length for sixteen years, finally leaving her in her second state. Gradually, however, the second personality was modified so that in old age it no longer represented a complete emotional opposition to her first state. Some measure of integration had evidently been achieved.
There have been many theories of the relation of phenomena to events in the brain. The theory of interaction is that physiological events affect mental events, and vice versa. This theory has not been popular