Transactional analysts for a long time and some still do use the original personality type model that was described by Paul Ware (TAJ 1983). He proposed six different personality types
Histrionic
Obsessive-compulsive
Paranoid
Schizoid
Passive-aggressive
Antisocial
Alternatively the DSM proposes ten
Histrionic
Obsessive-compulsive
Paranoid
Schizoid
Antisocial
Schizotypal
Borderline
Narcissistic
Avoidant
Dependent
In reality there are as many personality types as there are people on this planet, over 6 billion. But to have one for each person is of course meaningless as you don’t get any of the advantages of grouping them. The smallest number of personality types you could have would be 1. For example the personality type of ‘human’. This applies to everyone on earth and we know that this means they must breathe, have food require some form of human contact or they get marasmus and die. They all have the need to trust, belong, feel and so forth. Again however this is somewhat meaningless.
There are many systems that have two personality types
Introversion – extraversion
Active – passive
Withdrawing – Involving
There are others that have different numbers of personality types
Life positions
4 types by Ernst (TAJ 1971)
7 types by White (TAJ 1994)