A Brief Chronology of the
"Mars Effect" Controversy

More detailed chronologies can be found at Jim Lippard’s site
as well as in The Tenacious Mars Effect.

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L’Influence des Astres published, in which Michel Gauquelin outlines his discovery of a planet/profession connection in French births, including the Mars effect for sports champions. Gauquelin shows that Mars, Jupiter and Saturn tend to occupy two zones just after rise and culmination at the births of eminent professionals significantly more or less often than chance would allow. Mars, for example, occurs in these zones more often for generals, physicians and sports champions; less often for painters and musicians.


Gauquelin approaches the Belgian “Para Committee” with the request that they conduct an independent inquiry of his findings. His initial contacts are rebuffed.


Les Hommes et Les Astres published. Gauquelin replicates his planetary effects in new data for the same profession from other countries, along with additional findings for the Moon and writers.


Jean Dath, of the Para Committee, checks Gauquelin’s findings and says that he can find no statistical errors in what Gauquelin has done, suggesting an independent replication experiment with 500 Belgian athletes.


Para Committee begins an investigation of the Mars effect, completed a year later, which repeats Gauquelin’s original results using 535 European athletes. Over the next eight years the committee refuses to publish its results, until finally forced to do so.


Anti-astrology manifesto published in The Humanist, accompanied by article criticizing Gauquelin. Gauquelin and wife Françoise respond.


Summary report of Para Committee’s investigation published, with committee citing unspecified “demographic errors” as the reason their findings apparently support Gauquelin. Their own unpublished internal analyses show this to be incorrect, and Committee member Luc de Marré resigns in protest. In order to resolve this question, however, American statistician Marvin Zelen proposes the Gauquelins gather a control group of ordinary people born around the same date and in the same place as a group of sports champions, pointing out that Mars in the ordinary group should be present at a level significantly different from the champions if Gauquelin’s probability calculations are right and the Para Committee’s contention was wrong i.e., if demographic errors do not explain the replication. While the Zelen test is in progress, CSICOP researcher and astronomer Dennis Rawlins demonstrates privately that Gauquelin is in fact correct and the Para Committee wrong, further pointing out that the so-called “Zelen test” can only come out in Gauquelin’s favor. With Gauquelin unaware of this analysis, the test is allowed to proceed, and the data is completed and sent to Paul Kurtz in September.


At the end of April, CSICOP researcher George Abell writes a letter to Kurtz stating clearly that the Zelen test has come out in Gauquelin’s favor. Two reports on the experiment are published in The Humanist late in the year. The comparison between the Mars positions of 303 sports champions and 16,756 ordinary people shows that Gauquelin was right and the Para Committee was wrong, which is duly reported in an article by Michel and Françoise Gauquelin. However, despite Rawlins’ analysis and Abell’s private admission, an accompanying article by Zelen, Abell and Kurtz does not clearly convey the favorable outcome for Gauquelin, diverting attention from the issue by questioning the original champion data. This causes dissent and defections within the skeptics’ ranks, aggravating existing personal and intellectual conflicts and leading to open criticism such as that from CSICOP Fellow Richard Kammann, along with several resignations. Simultaneous with publication of the Zelen test results, CSICOP Chairman Paul Kurtz begins a study of the Mars effect based on U.S. athletes, in consultation with Zelen and astronomers George Abell and Dennis Rawlins.


The U.S. Mars effect study is published in The Skeptical Inquirer, the journal of the Committee for Scientific Investigation of Claims of the Paranormal (CSICOP). It shows a distinctly negative result, with Mars almost significant in the opposite direction from Gauquelin’s hypothesis.


Fate magazine publishes “sTARBABY,” written by Dennis Rawlins, a highly critical internal account of the conduct of CSICOP Council members in both the Zelen test and the U.S Mars effect study.


An article by Patrick Curry in the skeptic journal Zetetic Scholar, accompanied by commentaries from Michel Gauquelin and others, raises questions about the Zelen test and the CSICOP Mars study, paralleling Rawlins’ scientific criticisms. An article in Science et Vie accepting the CSICOP interpretation of the Zelen test and the U.S. Mars effect study is challenged by Michel Gauquelin. The Comité pour l’Étude des Phénomènes Paranormaux (CFEPP) proposes a new experiment and at Gauquelin’s insistence a detailed protocol spells out what will be done. From this point on, little is heard from the French committee, with the last contact occurring in 1985. Professor Suitbert Ertel of the University of Göttingen, who has in the meantime begun an exhaustive analysis of the Gauquelins’ work, is briefly in touch with committee members, with his last contact in 1986.


Abell, Kurtz and Zelen - responding to the criticism typified by Rawlins, Curry and Kamman - publish a “reappraisal” of the Mars effect experiments in Skeptical Inquirer 7(3), 77-82. They say, “Gauquelin adequately allowed for demographic and astronomical factors in predicting the expected distribution of Mars sectors for birth times in the general population.” In other words, the Para Committee’s contention about the reasons for its replication of Gauquelin were wrong.


Arno Müller and Suitbert Ertel’s initial investigations of the Gauquelins’ work is published in Zeitschrift für Parapsychologie und Grenzgebiete der Psychologie, 28, 1/2 (pp. 87-135). Mueller replicates Mars, but not Saturn, for prominent German physicians and notes that where his sample overlaps with Gauquelin’s he finds no problems with Gauquelin’s sampling practices. Ertel presents an overview of Gauquelin’s work, with an emphasis on its scientific nature, and reanalyzes some of Gauquelin’s data.


Suitbert Ertel’s extensive investigation into the Mars effect, published in The Journal of Scientific Exploration, offers firm support for the Mars effect. Ertel ranks all athletes in Gauquelin’s database (including his unpublished controls) according to the number of volumes in a standard set of references in which each is cited. He concludes that while there is evidence of a bias in Gauquelin’s determination of whether individual athletes belong in the champion or control groups, it actually serves to mask the Mars effect as shown in these “citation counts.” When the bias is corrected for, the effect is actually stronger, and not weaker.


Arno Müller publishes an analysis of 402 Italian writers. He does not replicate Gauquelin’s results showing significance for the Moon, but does report positive signficance for Jupiter and negative significance for Saturn, as with Gauquelin’s journalists.


The CFEPP issues a preliminary report on a study using 1,066 French sports champions, with Gauquelin receiving his copy in October. The report discusses methodology and lists the criteria by which data were selected, giving full data for the 1,066 and names of 373 who fit the criteria but for whom they could not obtain birth times. At this point it becomes evident that several points of the 1982 protocol have been violated, though Gauquelin expresses the hope that something might come of the situation nonetheless.


Gauquelin and Claude Benski of the CFEPP meet in his Paris laboratory to discuss differences between his data and theirs. In April, at age 62, Gauquelin commits suicide.


An article by Ertel in The Skeptical Inquirer uses the same methods as in his 1988 JSE article to demonstrate that the Mars effect is present in CSICOP’s own data.


The CFEPP report on the Mars effect is “leaked” to the Dutch newspaper Trouw at the time of a conference of Dutch skeptics. Speakers at the conference offer their own analysis of the CFEPP report, along with criticism of Gauquelin and Ertel, though no one outside skeptic circles has yet been provided with the CFEPP’s final report or data. Around the same time, Müller and Ertel publish their report of a replication of Gauquelin’s first study, of members of the French Académie de Médecine, with a sample that includes his original data and data for members admitted since his original study. They state:

The results confirm Gauquelin’s original 1955 findings. The predicted positive deviation from chance expectancy for Saturn is very significant, for Mars significant. An additional negative deviation for the moon is also apparent in both studies, but only in ours is the sample large enough for the deviation to reach significance. In both studies there also is a nonsignificant negative deviation for Jupiter. For each planet (sun and moon included) there is no significant difference between the deviations in Gauquelin’s sample (N=576) and those in our sample (N=915).


Ertel analyzes the CFEPP’s 1994 report in Correlation, contending that the Mars effect is evident, despite some serious flaws in the CFEPP experiment, including a bias toward low-eminence athletes and an incorrect calculation of the crucial “chance” level for Mars.


The CFEPP report, with an additional commentary by J. W. Nienhuys and several letters from Gauquelin to the Committee, is published as The Mars Effect, A French Test of Over 1,000 Sports Champions. The Committee says its own experiment showed no Mars effect and concludes that the effect was due to bias in Gauquelin’s data selection, offering as its main evidence several suggestions for changes in their list of athletes made by Gauquelin to the Committee. A critical review of this book by Kenneth Irving is published in Correlation 15(1). Around the same time, The Tenacious Mars Effect by Suitbert Ertel and Kenneth Irving is published, with a foreword by skeptic Jim Lippard and an abridged version of Lippard’s extensive chronology edited by Irving. Lippard’s foreword concentrates on the problems of partisan debunking and advocacy sparked by the controversy, urging a turn toward more serious investigation while not endorsing a specific view on Gauquelin’s claims. Irving provides a background of the history of the controversy and Ertel analyzes all data from the skeptic organizations, concluding that while the results in each case were affected by bias of one type or another, all three show the effect when citation counts are used. The book is reviewed by H. J. Eysenck in the same issue as Irving's review of the CFEPP's report.


Suitbert Ertel and Kenneth Irving analyze the question of “Biased Data Selection in Mars Effect Research,” in an article in the Journal of Scientific Exploration, dealing only with the question of how advance knowledge of Mars positions might have affected the various studies by both Gauquelin and skeptics. After a computer reanalysis of his work in 1984, Gauquelin had concluded that all of the planetary effects were best shown by including the areas just before rise and set along with the traditional “key sectors.” Reasoning that any bias due to foreknowledge of Mars positions would not have included these areas, Ertel and Irving calculate the ratio between the average number of cases in these newer “initial” sectors and the average number in the “main” sectors in order to look for evidence of such bias in all available data from both Gauquelin and the skeptics. This initial/main quotient (IMQ) confirms the bias previously shown in Ertel (1988) for Gauquelin’s unpublished control athletes, and shows no apparent difficulties of this type with the data set from the CFEPP. However, the IMQ for CSICOP shows an anomaly of the same size, direction and probability level as that for Gauquelin’s unpublished athletes, suggesting a high probability of bias influenced by knowledge of Mars sector positions during the CSICOP sampling process - i.e., the same as in the Gauquelin case. Though not offering a firm conclusion on this point, Ertel and Irving hold that until such time as an independent audit of the CSICOP files relating to the experiment can be made to settle the question, that data should be excluded from further consideration in regard to the Mars effect. In the Ertel and Irving article, they also report an anomaly of a different sort in the Para Committee data, from which an abnormally low IMQ is obtained. Following publication, and with the help of documentation provided by the Para committee, the anomaly is found to be due to rounding errors in data obtained from the Gauquelin laboratory, and on recalculation the IMQ for the Para data is found to be within normal range. This leaves the CSICOP data and the Gauquelin unpublished data as the only remaining anomalies. Replying in “Is the ‘Mars Effect’ Genuine? Paul Kurtz, J. W. Nienhuys and Ranjit Sandhu contend that Ertel and Irving are begging the question by drawing conclusions from a ratio based on an effect whose existence has not been demonstrated. In contrast to the Para committee, CSICOP refuses to allow an independent audit of their data.


Ertel and Irving file a rejoinder to Kurtz et al. with "The Mars Effect is Genuine," and the discussion ends there.