Gauquelin’s Mars Effect

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Michel Gauquelin (bron:,_Michel )

The Mars Effect kept skeptics quite busy for quite some time. One of the amazing things is how easily all kinds of skeptics were fooled and how quickly they launched themselves into investigations without examining properly the source of this effect. Rereading the original articles doesn’t lessen this feeling of amazement.

I have written several articles about this matter. One appeared in Skeptical Inquirer in 1997 and can be found here, and for two others I now give the references and a link.




  1. Paul Kurtz, Jan Willem Nienhuys, Ranjit Sandu (1997) Is the “Mars Effect” genuine? Journal of Scientific Exploration 11 (1), p, 19-39.
  2. Jan Willem Nienhuys (1997) Ertels “Mars Effekt”: Anatomie einer Pseudowissenschaft. Skeptiker 10 (3), p.92-98. The German version ‘Anatomie’ was a translation of an English text. This English text has been checked in 2017 and some comments are added.

My reason to come back to this in 2017 is a publication of many letters between Martin Gardner and Marcello Truzzi (Dear Martin / Dear Marcello: Gardner and Truzzi on Skepticism). Gardner considered the originator of the Mars Effect, namely the French psychologist Michel Gauquelin, a crank because he was such an ardent believer in his own nonsensical theory. Gardner compared him (on March 8) to the example of a man who believes that the center of the earth is made of jello – an example due to Freud. Gardner wrote (in a PS to his letter of March 5) what it was all about: ‘He presents nothing but one man’s analysis of one’s man [sic] accumulation of French statistics. … Claims of statistical correlations, to support wild theories, are a dime a dozen.’ Gardner thought that the wave of interest in astrology was the reason that Gauquelin’s books sold so well.

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