Astrology

Mesopotamian celestial divination

Assyriological scholarship places the earliest evidence for the interpretation of the night sky as ominous in a letter from the city of Mari of about 1765 BCE. By the early seventh century BCE, scribes at Nineveh known as the scribes of Enuma Anu Ellil, a series of about 70 tablets of celestial omens, received reports of observations and readings for the Assyrian court. These omens concerned mainly institutional and public matters such as the state and its ruler, not the fortunes of private individuals.

From omens to horoscopes

The earliest known horoscopes, from Babylon and Nippur, date to 410 BCE. Early examples recorded nativity data such as eclipses and conjunctions near the time of birth, which shows a link to the omen tradition. Later Seleucid and Parthian horoscopes listed the positions of the sun, moon and five visible planets on the day of birth, using the zodiac as a coordinate system. A reviewer of Francesca Rochberg's 2004 study notes her argument that separating divination, astrology and mathematical astronomy in Mesopotamia is a twentieth-century construction.

Hellenistic horoscopic astrology

The Internet Encyclopedia of Philosophy entry on Hellenistic astrology says that Greek-language astrology grew from Babylonian foundations with Egyptian and Persian influences. It credits the Babylonian priest Berossus with introducing astrology to Greek-speaking regions around 280 BCE and dates technical Greek manuals of horoscopic astrology to the late second century BCE. Surviving later authors include Manilius in the first century BCE, Claudius Ptolemy, whose Tetrabiblos is dated to about 100 to 170 CE, and Vettius Valens, active around 152 to 162 CE.

India and China

David Pingree's entry on Sphujidhvaja states that his Yavanajataka was composed in 269 CE as a versification of a Sanskrit prose translation, made in 149 CE, of a Greek astrological textbook. Pingree treats this work as foundational for later Indian astrology of birth and of questions. The same entry hedges the date of earlier Indian astral texts, and the sources reviewed do not allow a fuller account of the Indian tradition. Pingree's dating is a scholarly reconstruction that other researchers may revise.

In China, Xiaochun Sun describes tianwen, literally patterns in the sky, as portent astrology, concerned mainly with state affairs such as war, famine, flood and court politics. Sima Qian served as Grand Astrologer to Emperor Wu of the Former Han around 100 BCE, and Han thinkers such as Dong Zhongshu linked abnormal celestial events to the conduct of the ruler. Sun's paper does not cover personal birth-time astrology.

One word, several practices

The word astrology now covers practices with different aims and different assumptions. Mesopotamian celestial divination read the sky for signs about the state, Chinese tianwen read it as warnings about government, and horoscopic astrology cast a chart for a particular birth. The labels are modern and apply across traditions with different aims. Resemblance between the traditions should not be read as proof that they are one practice.

Horoscope, natal and katarchic astrology

The Internet Encyclopedia of Philosophy defines a horoscope as a list of planetary positions against the zodiac, cast for the exact time and place of birth. It distinguishes natal astrology, which makes predictions from a birth chart, from katarchic astrology, which selects auspicious times for an activity or investigates past events. Pingree's entry uses a related pair of terms, genethlialogy for astrology of birth and interrogational astrology for answering questions.

Sun-sign columns and Indian usage

Geoffrey Dean's review separates sun-sign material found in newspaper columns, which assigns traits or forecasts to one of twelve signs by birth date, from the whole-chart readings of an astrologer. One study of Indian astrology, by Bhandary and colleagues, describes the system it tested as that of Varahamihira, a named Indian authority, and the sources reviewed here do not otherwise define Indian terms such as jyotisha.

What a chart records

In the surviving horoscopic tradition a chart is a calculation, not an observation made at the moment of reading. The Seleucid and Parthian horoscopes described by Rochberg's reviewer give the positions of the sun, moon and visible planets on a given day, and modern studies describe charts generated by computer from a person's date, time and place of birth, with gender recorded in at least one Indian study.

Readings as they appear in the studies

In controlled tests, the practice takes the form of astrologers interpreting a chart and then either matching it to a personality profile, as in the Carlson study, or to a case file, as in the McGrew and McFall study, or estimating a feature such as academic ability or mental illness. In two of the studies the design was agreed with astrological organisations beforehand, but the tasks remain an approximation of a consultation and not a record of one.

What the sources do not describe

None of the sources reviewed describes a typical consultation, its length or cost, how astrologers are trained, or whether any jurisdiction regulates the activity. A reader asking about any of these would need other sources, and statements about consultation formats found elsewhere should not be assumed to apply to every tradition described on this page.

Uses within the traditions

In the traditions described by the sources, claimed uses depend on the form. Mesopotamian and Chinese celestial divination were used to read signs about kings and states, and Chinese portent astrology fed into political argument about the ruler's conduct. Hellenistic natal astrology made predictions from a birth chart, and katarchic astrology chose times for undertakings.

Modern claims that have been tested

Several modern claims have been put to test. These include that a natal chart describes personality traits, as in Carlson's study, that it can be matched to a person's life history, as in McGrew and McFall, that it indicates academic ability, as in Narlikar and colleagues, and that it indicates the presence of mental illness, as in Bhandary and colleagues. Dean's review also lists tests of sun-sign compatibility in marriage and of whether people born at the same time resemble one another.

Belief and use among the public

A 2022 scoping review of belief in astrology and fortune-telling by Das and colleagues reports that interest in astrology appeared to surge during the Covid-19 pandemic, possibly in response to uncertainty. It describes belief as associated with thinking style, self-concept verification and stress. The review does not report what people gain from readings, and claimed benefits for wellbeing or decision-making are outside what its sources examine.

Blinded matching tests

Carlson's 1985 double-blind test, reported in Nature, was designed with advising astrologers from a national astrological research organisation. In the earlier report version, 28 astrologers accepted invitations and each was given a natal chart with three personality profiles from the California Psychological Inventory to choose from. The first-choice hit rate was 0.34 with an error of 0.044, close to the 0.33 expected by chance and well below the 0.5 the astrologers had agreed beforehand. The published Nature article was not available in full, so these figures come from the report version.

McGrew and McFall's 1990 study used a protocol approved by the Indiana Federation of Astrologers. Six astrologers independently tried to match 23 birth charts to case files of volunteers, which included life histories, photographs and test profiles. They did no better than chance or than a non-astrologer control, and they did not agree with one another. The authors also point out that in Carlson's study the volunteers could not select their own profiles either, so they regard that part of his result as inconclusive.

Other tests of specific claims

Narlikar and colleagues sent 40 randomised charts to each of 51 astrologers in Maharashtra, of whom 27 returned assessments, asking them to identify which charts belonged to high-achieving students and which to students with intellectual disability. The success rate was marginally below that expected by coin-tossing, and 200 charts given to representatives of an astrology institute did no better. Wyman and Vyse gave 52 college students a true and a bogus summary each. Students identified their personality-inventory results above chance but could not identify their real astrological summaries, and both kinds of summary showed a Barnum effect, in which people rate generic descriptions as accurate.

A positive-leaning finding and critiques of the tests

A study by Bhandary and colleagues reported results more favourable to astrology. Four blinded astrologers read computer-generated charts for 150 people, 75 of whom had a mental illness, and agreement with clinical status was moderate for lifetime illness and substantial for current illness. Sensitivity and specificity were above 75% for lifetime illness. Prediction of symptom pattern and onset was poor, inter-astrologer agreement was good only for lifetime illness, and the authors call their findings tentative. The sources reviewed did not include a replication.

Kenneth McRitchie, who argues for astrological research, contends that Dean and Kelly's 2003 meta-analysis mixed disparate kinds of study and that Carlson's and Gauquelin's work support astrological claims. Dean's 2016 review, in turn, reports 69 matching studies clustering around zero accuracy and a test of 144 sun-sign pairings in about 10 million UK marriages that found no significant difference from chance. These are opposed interpretations of overlapping literature, and neither was a systematic review with a reported search method in the form retrieved.

What the tests can and cannot show

The tests reviewed examine specific claims, mostly that a chart can be matched to a person or group. A null result in a matching task does not test every astrological tradition or technique, and McRitchie argues that Carlson's own data support astrological claims. A result close to chance in a task agreed with astrologers tells a reader about that task, and it does not establish what readings mean to the people who use them.

Interpretive limits and source quality

Dean's article is a review in a magazine and the McRitchie commentary is posted on an astrology-related site, so neither is a neutral systematic review. Several tests used small samples or few astrologers, and Narlikar and colleagues describe their own procedure as limited. The Barnum effect, shown in the Wyman and Vyse study, offers one explanation for why readings can feel accurate, but it does not by itself show how any individual reading was received.

Care boundaries

Astrology is not a medical, legal or financial service. The Bhandary study found poor prediction of symptom pattern and timing of illness, and no source reviewed supports using a chart to diagnose, to rule out a condition or to decide on treatment. A person with symptoms, or in distress, should not delay or replace necessary professional care in favour of a reading.

Reported harms and consumer concerns

Das and colleagues describe case studies of what they call fortune-telling addiction, with distress, cravings and salience, and say that excessive engagement may carry mental health risks. They add that the condition needs further research. Dean's review cites an astrologer who offered services for fertility treatment despite statistically insignificant results in her own thesis, as an example of possible exploitation of people in vulnerable situations. Both are limited evidence of harm and do not give its frequency.

Training and regulation

The sources reviewed do not cover training standards, professional registers or regulation of astrologers in any jurisdiction. Requirements, if any, differ by country, and this page does not state them.