Two personalities - is it normal?

[introverted]

Darwinian evolutionary theory
http://www.darwins-theory-of-evolution.com/

Splitting
Idealization and devaluation
Obsessive-Compulsive - Compensatory Narcissistic - Passive-Aggressive
Psychoticism-Neuroticism
http://www.tandfonline.com/doi/abs/10.10...65#preview
Paranoid-Schizoid - Paranoid/Schiziod(Manic)-Depressive

Freudian psychology - The Ego and the Id
I.D (Idealized self)
http://www.ptypes.com/idealized_self.html
Ego ideal
http://www.ptypes.com/ego-ideal.html

The four temperaments
http://www.ptypes.com/temperaments.html

E. Kretschmer's Physique and Character
Personality types -Evolutionary Psychology - prototypal
Schizothymic (Detachment theory) Apollonian Sublimation
Cyclothymic (Attachment theory) Dionysian Splitting and Projective Identification
http://www.ptypes.com/temperaments.html#kretschmer
Cyclothymes Schizothymes
http://www.ptypes.com/main-interests-types.html

Jungian Psychological Typology Introvertism-Extrovertism
http://www.socionics.com/main/types.htm

Five-Factor Model
http://www.personalityresearch.org/bigfive.html

Histories worked 1-2-4-8-16 so guessing its within the norm