Psychological astrology, or astropsychology, is the result of the cross-fertilisation of the fields of astrology with depth psychology, humanistic psychology and transpersonal psychology. There are several methods of analyzing the horoscope in the contemporary psychological astrology: the horoscope can be analysed through the archetypes within astrology (as is characteristic for Jungian approach in astrology) or the analyses can be rooted in the psychological need and motivational theories. There might exist other astrological methods and approaches rooted in psychology. Astrologer and psychotherapist Glenn Perry characterises psychological astrology as "both a personality theory and a diagnostic tool".
In the twentieth century, esoteric tradition inspired Carl Jung, Swiss psychiatrist and founder of analytical psychology, to formulate his archetypal hypothesis from Plato's theory of ideas or forms. In his research into the symbolic meaning of his patient's dreams, conversations and paintings, Jung observed recurring mythical themes or archetypes. He proposed that these universal and timeless archetypes channel experiences and emotions, resulting in recognizable and typical patterns of behavior with certain probable outcomes. Jung claimed to observe a correlation between these archetypal images and the astrological themes or traditional 'gods' associated with the planets and signs of the zodiac. He concluded that the symbolic heavenly figures described by the constellations were originally inspired by projections of images created by the collective unconscious. Jung wrote "Astrology represents the sum of all the psychological knowledge of antiquity".
In collaboration with pioneer theoretical physicist (and Nobel laureate) Wolfgang Pauli, Jung developed the theory of synchronicity. This theory, which Jung compared to Aristotle's formal causation, poses that "whatever is born or done at this particular moment of time, has the quality of this moment of time". Accordingly, astrological claims of correlations between the position of heavenly bodies at the time of birth and an individual's development were defined by Jung as being acausal and not directly caused by the planets.
Several astrologers as well as psychologists pursued Jung's theories in their writings, teachings and practice. One of the first astrologers to combine Jungian psychology with astrology was Dane Rudhyar and his protégé, Alexander Ruperti. Rudhyar termed it "humanistic astrology," the subject of his monumental volume, The Astrology of Personality, published in 1936. Psychological astrology, however became firmly established in the late 20th century with the books and lectures of Liz Greene and Stephen Arroyo who were both strongly influenced by the Jungian model. In 1983, Liz Greene and Howard Sasportas, a psychosynthesis psychotherapist, founded the Centre for Psychological Astrology in London.
Meanwhile, in Switzerland, Bruno Huber & Louise Huber also developed their own method of astrological psychology, referred to as the Huber Method which was influenced by Roberto Assagioli's work with psychosynthesis. In 1962, the Hubers founded the Huber School of Astrology and their work is now taught at the Astrological Psychology Association.
Possibly the most widespread application of Jung's theories is through the Myers-Briggs Type Indicator (MBTI) assessment developed during the Second World War. CPP Inc., the publisher of the MBTI instrument, calls it "the world’s most widely used personality assessment", with as many as two million assessments administered annually. This psychometric questionnaire is designed to measure psychological preferences in how people perceive the world and make decisions.:1 These preferences were extrapolated from the typological theories proposed by Jung and first published in his 1921 book Psychological Types. So the authors, Briggs and Myers adapted Jung's four psychological types,:xiii which were based on the four elements of classical cosmology on which the zodiac, with its corresponding human character traits, was structured. Nicholas Campion comments that this is "a fascinating example of 'disguised astrology', masquerading as science in order to claim respectability."
Other psychological approaches
Back in 1970's, in the twelve-volume series, The Principles and Practice of Astrology (Llewellyn 1975), Noel Tyl has allied the psychological need theory with astrological symbolism. This analytical blend is developed fully in his book Holistic Astrology - The Analysis of Inner and Outer Environment (1980). In the light of the psychological need theory, he interprets the horoscope "as a process of lifelong conditioning, where individuals are predisposed to present individualized needs to the environment. .... This processs identifies how we act, who we are, and how we fit into the world. Fulfilling destiny, in modern terms, is fulfilling needs." 
While psychological astrology brings a transpersonal dimension and spiritual notions to psychology by linking the psyche to the Cosmos, psychological astrology is "decidedly not deterministic". Nor is an individual's everyday life ruled by malefic or benefic planets as the horoscope is considered a mere tool to help identify an individual's nature and potential for psycho-spiritual growth.
Psychological astrology has been criticized for confirmation bias and astrology is widely considered a pseudoscience by the scientific community. In psychology and cognitive science, confirmation bias is a tendency to search for or interpret new information in a way that confirms one's preconceptions and avoids information and interpretations that contradict prior beliefs.
The largest and most recognized study of the claims of astrology was published by Shawn Carlson in "Nature". Twenty-eight professional astrologers agreed to participate, including several who were strongly influenced by the Jungian model. Carlson concluded that the astrologers were unable to match horoscopes with profiles compiled using the California Psychological Inventory (CPI) in blind tests any better than chance.
- Astrological symbols
- Astrology and alchemy
- Astrology and astronomy
- Astrology and computers
- Planets in astrology
- Season of birth
- Maslow's hierarchy of needs
- Perry, Glen, Dr. What is Psychological Astrology?, Association for Psychological Astrology, http://www.aaperry.com/index.asp?pgid=64 retrieved July 2011
- Tarnas, R., The Passion of the Western Mind: Understanding the Ideas that Have Shaped Our World View, Ballantine Books (1993) ISBN 0-345-36809-6
- Definition of an Archetype. retrieved July 2011
- Jung, C.G. The Structure and dynamics of the Psyche, Collected Works Vol.8, (Princeton University Press, NJ 1960) para.325
- Campion, Nicholas, History of Western Astrology, (Continuum Books, London & New York, 2009) ISBN 978-1-84725-224-1, Comments on Jung pp.251-259
"Jungian Analyst, Liz Greene." p.258
- Jung, Carl G., 'Richard Wilhelm: In Memoriam' in The Spirit of Man, Art and Literature, Collected Works, Vol.15 (translated R.F.C.Hull), Routledge, Kegan and Paul, London. (1971), p.56
- Gieser, Suzanne. The Innermost Kernel, Depth Psychology and Quantum Physics. Wolfgang Pauli’s Dialogue with C.G.Jung, (Springer, Berlin, 2005) p.21 ISBN 3-540-20856-9
- Jung, C. G. Synchronicity: An Acausal Connecting Principal." Routledge, 1985
- Campion, Nicholas. "Prophecy, Cosmology and the New Age Movement. The Extent and Nature of Contemporary Belief in Astrology."( Bath Spa University College, 2003) via Campion, Nicholas, History of Western Astrology, (Continuum Books, London & New York, 2009) p.248 pp.256-257 ISBN 978-1-84725-224-1
- Rudhyar, Dane, "The Astrology of Personality: A Re-Formulation of Astrological Concepts and Ideals, in Terms of Contemporary Psychology and Philosophy", Aurora Press (1936, Reprinted December 1987) ISBN 0-943358-25-6
- Holden, James, A History of Horoscopic Astrology: From the Babylonian Period to the Modern Age, (AFA 1996) p.202 ISBN 0-86690-463-8
- Hand, Robert, Horoscope Symbols (Para Research 1981) p.349 ISBN 0-914918-16-8
- Hyde, Maggie. Jung and Astrology. (Aquarian/Harper Collins, 1992) p.105 ISBN 1-85538-115-X http://www.skyscript.co.uk/synchronicity.html
- History of the Centre for Psychological Astrology http://www.cpalondon.com/history.html
- About the Hubers and the Astrological Psychology Association retrieved July 2011
- "CPP Products". Retrieved 2009-06-20.
- Myers, Isabel Briggs with Peter B. Myers (1995) . Gifts Differing: Understanding Personality Type. Mountain View, CA: Davies-Black Publishing. ISBN 0-89106-074-X.
- Jung, Carl Gustav (August 1, 1971). "Psychological Types". Collected Works of C.G. Jung, Volume 6. Princeton University Press. ISBN 0-691-09770-4.
- Phillipson, Garry & Case, Peter. The Hidden language of modern Management Science: Astrology, Alchemy and the Myers-Briggs Type Indicator', Culture and Cosmos 5(2) (Autumn/Winter 2001) pp.53-72
- Ptolemy. Tetrabiblios (ca.150 CE) Ch. XXI translation by J M Ashmand "Ptolemy's Tetrabiblos, or Quadripartite: being four books of the influence of the stars". Harvard University (1822) "... the twelve signs are, therefore, distributed among four equilateral triangles."
Valens, Vettius, The Anthology by Vettius Valens (150-175 CE) Book II, Chapter 1 - translated by Robert Schmidt — The Golden Hind Press, Berkeley Springs, WV, (1994)."The Sun, being truly fiery, was associated with Aries, Leo, and Sagittarius, which was named its diurnal trigon and is also fiery by nature ... Taurus, Virgo, and Capricorn – which is truly earthy... the airy trigon, Gemini, Libra, and Aquarius... the watery trigon Cancer, Scorpio and Pisces"
- Campion, Nicholas. A History of Western Astrology. Volume II. Continuum Books, London (2009) ISBN 978-1-84725-224-1 p.259
- Tyl, Noel (1980). Holistic Astrology: The Analysis of Inner and Outer Environments. Llewellyn Publications. ISBN 0935620001.
- Tyl, Noel (2002). Synthesis & Counseling in Astrology: The Professional Manual. Llewellyn Publications. ISBN 978-1567187342.
- Plous, Scott, The Psychology of Judgment and Decision Making, McGraw-Hill (1993), ISBN 978-0-07-050477-6
- Muller,Richard. Web site of Richard A. Muller, Professor in the Department of Physics at the University of California at Berkeley, "My former student Shawn Carlson published in Nature magazine the definitive scientific test of Astrology." Link retrieved:2 August 2010
Maddox,Sir John, editor of the science journal Nature, commenting on Carlson's test (1995) "... a perfectly convincing and lasting demonstration." Link retrieved: 2 August 2011
- Shawn Carlson A Double-blind Test of Astrology Nature, 318: pp.419-425 (1985)
p.420 Carlson states that 28 astrologers vouched for by NCGR accepted their invitation to participate, but does not state how many astrologers participated.