Transpersonal psychology, or spiritual psychology, is a sub-field or school of psychology that seeks to integrate the spiritual and transcendent aspects of the human experience with the framework of modern psychology. The transpersonal is defined as "experiences in which the sense of identity or self extends beyond (trans) the individual or personal to encompass wider aspects of humankind, life, psyche or cosmos". It has also been defined as "development beyond conventional, personal or individual levels".
Issues considered in transpersonal psychology include spiritual self-development, self beyond the ego, peak experiences, mystical experiences, systemic trance, spiritual crises, spiritual evolution, religious conversion, altered states of consciousness, spiritual practices, and other sublime and/or unusually expanded experiences of living. The discipline attempts to describe and integrate spiritual experience within modern psychological theory and to formulate new theory to encompass such experience. The Transpersonal Psychology Day is celebrated on February 27.
In 1968 Abraham Maslow was among the people who announced transpersonal psychology as a "fourth force" in psychology, in order to separate it from Humanistic psychology. Early use of the term "transpersonal" can also be credited to Stanislav Grof and Anthony Sutich. At this time, in 1967–68, Maslow was in close dialogue with both Grof and Sutich regarding the name and orientation of the new field. According to Powers the term "transpersonal" starts to show up in academic journals from 1970 onwards.
Both Humanistic and Transpersonal psychology have been associated with the Human Potential Movement, a growth center for alternative therapies and philosophies that grew out of the counter-culture of the 1960s at places such as Esalen, California.
Gradually, during the 1960s, the term "transpersonal" was associated with a distinct school of psychology within the humanistic psychology movement.