Does astrology predict anything? What 40 years of controlled tests found

By Yulia Myronova · Published 12 October 2026

In short: no. When astrology has been tested under controlled conditions — can astrologers match charts to people, do people born minutes apart turn out alike, do zodiac signs predict earnings — the results have been at the level of chance. One historical anomaly remains disputed. What survives is not prediction but something smaller: a structured way to think about time.

We run a Jyotish service, and we start here on purpose. A service that hides this should not be trusted with your decisions.

Test 1: can astrologers match a chart to a person?

The best-known single study is Shawn Carlson's double-blind test, published in Nature in 1985. Twenty-eight astrologers tried to match 116 natal charts to personality profiles. They did no better than chance.

The result is still argued over. Suitbert Ertel re-analysed it in 2009 using the protocol's own pre-agreed scoring and found a borderline result (p = 0.054 on matches, and p = 0.037 on ten-point ratings). His conclusion was cautious: not enough to call astrology confirmed, but enough to call Carlson's verdict unsound.

Geoffrey Dean and Ivan Kelly (2003) reviewed the wider field: more than 40 controlled studies with about 700 astrologers and 1,150 charts. The average accuracy effect was 0.051 — statistically indistinguishable from zero.

Test 2: do astrologers agree with each other?

If a chart carried clear information, trained readers should agree about it. Across 25 studies with about 500 astrologers, the agreement between them averaged 0.101 (Dean & Kelly, 2003). For a test to be used on individuals, the usual requirement is around 0.8. The field does not converge.

Test 3: do people born at the same moment turn out alike?

This is the cleanest test, because it needs no interpretation at all. Dean and Kelly studied 2,101 people born in London between 3 and 9 March 1958, on average 4.8 minutes apart. Across 110 variables measured at ages 11, 16 and 23, "time twins" were no more alike than anyone else. The effect attributable to astrology came out at 0.00 ± 0.03.

Test 4: do signs predict life outcomes at scale?

Big datasets now make this testable directly:

Earnings and careers. Collischon and Zimmermann (2026) used German administrative data with more than 11 million observations. Comparing only people born within seven days either side of a sign boundary, the effect of sign on earnings, education and managerial position was zero. Apparent raw differences came from school-entry cut-off dates, not the sky.
Personality and intelligence. Hartmann, Reuter and Nyborg (2006) found one significant result out of 35 tests across more than 15,000 people, worth less than one IQ point.
Wellbeing. Joshanloo (2024) found sign no more predictive of wellbeing than a random category, across 12,791 people.

Our own test of classical Jyotish wealth rules on 152 certified charts found nothing either — details here.

The one anomaly that has not gone away

Michel Gauquelin reported that Mars appeared in certain sectors of the sky for 22% of 2,088 European sports champions, against 17% expected. Replications where he did not collect the data found smaller figures — 13.5% in a US sample, 18.66% against a 17.70% baseline in a French one. Supporters and sceptics still disagree about whether the effect is real or an artefact of how birth times were reported. It is honest to call it unresolved — and also honest to note that it is about a narrow sector rule and sports, not about predicting events in a person's life.

Why readings feel accurate anyway

In Dean's reversed-chart experiment (1987), people received readings — half genuine, half written to say the exact opposite of their chart. The genuine readings were rated 96% accurate. The reversed ones: 97%. This is the same effect Forer demonstrated in 1949: general descriptions feel personal. It holds for sceptics too (Glick, Gottesman & Jolton, 1989).

So what is left?

If astrology doesn't predict, why do so many people use it? Roughly 3 in 10 US adults consult astrology, tarot or fortune tellers at least once a year (Pew Research Center, 2025). In our reading, people come with two questions: which path do I commit to? and is it me, or is it the moment? Neither is really a request for a forecast. Both are decisions someone is trying to make with nothing to hang them on.

That is the narrow job Vedic AI Guru tries to do honestly:

Structure, not prediction. A reading shows when pressure on one decision rises and eases, never how it turns out.
Statements that can be wrong. Each comes with "how you'll know we were wrong", so you can check it against your own life.
No pretending. No probabilities, no yes or no, and no answers on health, money amounts, investments, pregnancy, lawsuits or death.

A compass, not an autopilot. The decision stays yours.

How a reading works, and what we won't answer: Questions and answers

Sources - Carlson, S. (1985). A double-blind test of astrology. Nature, 318, 419–425. https://doi.org/10.1038/318419a0 - Collischon, M., & Zimmermann, F. (2026). Is your career determined by the stars? Western zodiac signs and labor market outcomes in Germany. Kyklos. https://doi.org/10.1111/kykl.70057 - Dean, G. (1987). Does astrology need to be true? Part 2: The answer is no. Skeptical Inquirer, 11(3), 257–273. - Dean, G., & Kelly, I. W. (2003). Is astrology relevant to consciousness and psi? Journal of Consciousness Studies, 10(6–7), 175–198. - Ertel, S. (2009). Appraisal of Shawn Carlson's renowned astrology tests. Journal of Scientific Exploration, 23(2), 125–137. - Forer, B. R. (1949). The fallacy of personal validation. Journal of Abnormal and Social Psychology, 44(1), 118–123. https://doi.org/10.1037/h0059240 - Glick, P., Gottesman, D., & Jolton, J. (1989). The fault is not in the stars. Personality and Social Psychology Bulletin, 15(4), 572–583. - Hartmann, P., Reuter, M., & Nyborg, H. (2006). The relationship between date of birth and individual differences in personality and general intelligence. Personality and Individual Differences, 40(7), 1349–1362. - Joshanloo, M. (2024). The sun's position at birth is unrelated to subjective well-being. Kyklos. https://doi.org/10.1111/kykl.12395 - Pew Research Center (2025). 3 in 10 Americans consult astrology, tarot cards or fortune tellers. https://www.pewresearch.org/religion/2025/05/21/3-in-10-americans-consult-astrology-tarot-cards-or-fortune-tellers/ - Rawlins, D. (1979–1980) and Benski, C. et al. (1996), replications of the Gauquelin Mars effect.