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Two Problems With the Scientific Study of Astrology

July 2010

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The Failure of Astrology to Achieve Statistical Validation

In the 1950s, when Michel Gauquelin, John Addey and a tiny handful of others were beginning their research, there were virtually no studies available that had put astrology to a scientific test. Today there are at least 100 studies published in psychological journals and 400 in astrological journals, “equivalent to about 200 man-years of scientific research” (2). Some of these studies were conducted by scientists; some by astrologers; some were obviously biased; some were not. In nearly every single case, astrology has failed the test to which it was put. According to a summary by Wikipedia, these studies “have repeatedly failed to demonstrate statistically significant relationships between astrological predictions and operationally-defined outcomes. Effect size tests of astrology-based hypotheses conclude that the mean accuracy of astrological predictions is no greater than what is expected by chance” (3). Anyone who objectively reviews the research to date will see that this is true.

The one piece of scientific evidence that has stood the statistical test against an unrelenting half-century onslaught of criticism is the controversial Mars effect, documented extensively by Michel Gauquelin in 1955. This is a mighty wobbly statistical peg on which to hang our scientific hat. In the end, most researchers reviewing the available scientific studies as a whole form pretty much the same conclusion as Michel Gauquelin himself, who said, "The casting of horoscopes provides a living to thousands of individuals and provides dreams to an infinitely larger number of consumers. ... [But] since the most painstaking studies have shown the inanity of horoscopes, there should be a strong rising up against this exploitation of public credulity" (4).

Gauquelin drew this conclusion in 1979, after analyzing the horoscopes of 16,000 famous people. If the preeminent scientific researcher among us has dismissed astrology on scientific grounds, after conducting extensive scientific research, then how can we continue to pretend that science will ultimately validate astrology? Despite the brisk reality check of research to date, and the conclusions of serious researchers such as Gauquelin, there are those among us who still insist that with better, more sophisticated or more lenient or less biased research models, we can still prove the validity of astrology scientifically. I, for one, do not believe this is ever going to happen.

The Limitations of Qualitative Research

In particular, there has been recent enthusiasm about the idea that we can effectively approach a scientific validation of astrology through qualitative research, increasingly adopted by soft sciences as a more appropriate research methodology . While it is likely that this approach is more amenable to a scientific study of astrology than the statistical model that has historically been applied, its usefulness as a pathway to validation of astrology is not quite as promising as its proponents seem to imply. This is so for two reasons.

First, though qualitative research has gained increasing begrudging respect in the last 20-30 years, it is still an evolving methodology struggling with its own credibility issues. As one qualitative researcher states the problem (6):

"For many scientists used to doing quantitative studies the whole concept of qualitative research is unclear, almost foreign, or 'airy fairy' - not 'real' research. Clinical scientists sometimes find it difficult to accept this research method where the generation of hypotheses often replaces the testing thereof, explanation replaces measurement, and understanding replaces generalisability."

Secondly, unlike other soft sciences for which qualitative research methods are more useful and appropriate, astrology faces a philosophical hurdle on the road to validation that these other disciplines do not. Astrology is currently attempting to dig itself out from under the deficit label “pseudoscience,” in part because it is considered by scientists to be bastardized form of astronomy. If you look at the history of astrology, this is not that far from the truth, since at one time (say prior to the 7th century CE), astrology and astronomy were inseparable – both encompassed under the study of astrologia. Since then, astronomy has continued along strictly scientific lines, while astrology has gone a different route.

Because of this heritage, the bar is a bit higher for astrology than it is for psychology, let’s say, which emerged from its inception in the laboratories of William Wundt and other behaviorists as a hard science, backed by research, to gradually occupy the broader and softer umbrella it encompasses today. Western astrology, by contrast, arose as a divinatory art in Babylonia. Later during the Hellenistic period, it was modified by the Greeks as a logical system, thoroughly intertwined with the mythopoetic worldview against which the emerging protoscience of the era arose in contrast and rebellion . The attempt to recast astrology as a science is a relatively recent development – less than 100 years old – which runs counter to our 4,000-year old history. To simply call ourselves a Johnny-come-lately soft science, and take shelter in qualitative research – even if we could prove our validity by non-statistical methods – will do nothing to keep our detractors at bay, since it is obvious to them, if not to us, that we are merely attempting to graft science onto a poorly suited root stock.


(2) Smit, Rudolf. “Grand Summary of Entire Web Site,” Astrology and Science. 4 November 2009.

(3) “Astrology: Research.” Wikipedia. 4 November 2009.

(4) Gauquelin, Michel. Dreams and Illusions of Astrology. Buffalo, NY: Prometheus Books, 1979, p. 158.

(5) Perry, Glenn. “Causality, General Laws and Astrological Research” in International Astrologer, Summer, 2005, Vol XXXIII, Number 3, p. 42.

(6) Labuschagne, Adri. “Qualitative Research – Airy Fairy or Fundamental.” The Qualitative Report, March 2003, Volume 8, Number 1. 4 november 2009.

The next post in this series is Astrology Yields Subjective Truth, Science Demands Objectivity.

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