psyche, has both a conscious and an unconscious level. He expanded the notion of the
unconscious to a new concept, which is personal unconscious, refers to those psychic
images not sensed by the ego that brings the meaning of all human beings to share
certain unconscious ideas because humans were created from similar evolutionary
circumstances and common ancestors. He divided the unconscious into 2 groups,
personal unconscious that contains the complexes such as emotionally toned groups
of related ideas and collective unconscious that includes various archetypes (Feist &
Feist, 2013). He also proposed and developed the concepts of the extraverted and the
introverted personality, psychological function, and development of personality based
on his view. His work has been influential in psychiatry and the study of religion,
literature, and related fields.
Paul Costa and Robert R.McCrae are an exceptionally beneficial research team that
has cooperated since they initially met in Boston in 1975. Their more than 250
publications on personality traits and the Five Factor model have had a significant
effect on personality assessment, theory, and research. Robert R. McCrae (1949 until
now) is a personality psychologist at the National Institute of Aging. He has spent his
career studying the stability of personality across age and culture. Alongside Paul
Costa, he is a co-creator of the Revised NEO Personality Inventory. Paul Costa, Jr.
(1942 until now) is an American psychologist and author of over 300 academic
articles. He is perhaps best known for the Revised NEO Personality Inventory. Costa
and McCrae’s exploration mirrors their suffering enthusiasm for the scientific study of
personality by which individuals vary from each other. They proposed the “The Big 5
Invention”, the five basic dimensions of personality includes extraversion (also often
spelled extroversion), agreeableness, openness, conscientiousness, and neuroticism.