Re-evaluating the Gauquelin Data

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PAGES

1. Introduction
2. Expected and Observed planetary frequencies in the Gauquelin professional groups
3. The Ertel Enigma
4. Report by the French Skeptics, 1982-96
5. The Work of Arno Müller
6. From the Archives
7. Synastry Effects in the Gauquelin 'Heredity' Data
8. Poets and the Moon
9. Character traits
10. Venus
11. Database of Character-Traits
12. Introvert-Extravert
13. Physicians and Sports Champion Data
14. Where's the Data?
15. Was It Significant?
16. A Fourfold Effect
17. The Shape of the Gauquelin Professional-Data Effect
18. Astro-Psychological Problems
19. Françoise and Michel, a Productive Partnership

15. Was it significant?

Astonishingly high significance levels were claimed by MG for his groups of professional data, as published for example in a British psychology journal in 1975¹:

Those significance-levels were derived using a chi-squared test: eg, his group of Jupiter-military reached chi-square = 29, which gave that very high significance level.²

However, a primary axiom of probability theory is that no significance test should be performed on the set of data from which a prediction is made: but only on some further set of data, on which it is tested. The significance test can then tell, whether or not the initial effect has replicated. Michel never seemed to grasp this subtle point.

We've seen (page 14) that there were two main stages of his data-release: the first in 1955 (L'Influence des Astres) which was then followed in 1970 by the data-volumes. The first proposed the hypotheses to be tested. MG's quoted probability-values were derived from the 1970-72 data.

We therefore need to subtract the initial, 1955 data from the final set, to ascertain if anything has replicated, and judge its significance. Thus, for physicians³:

Saturn in Key Sectors for Physicans - Did it Replicate?
Physicians	Total	KS Expect	Observed	% Excess	Chi-Square
1955	576	96	130	35%	12
1970	2552	425	486	14%	9
2018 Difference	1976	329	356	8%	2

Chi-Squared = 2 so the physicians-and-Saturn hypothesis fails to attain statistical significance, it did not replicate.

Let's do the same from sports champions and Mars, this time comparing published vs 'correct' values (See Page 13).

Mars and Sports champions - did it replicate?
	Total Sports	Key Sector Scores	Expected Score	% Excess	Chi-Square	Probability
1. MG 1955	570	68+68=136	97.8	39%	32	1 in 70,0004
2. NK 2018	570	59+67+126	99.85	26%	7	1 in 20
3. M&FG 1972	2088	240+212=452	365.4	24%
4. CURA 2018	2088	227+208=435	365.4	19%	13
Difference 4-1	1518	299	256.6	13%	4

A Chi-square value of 4 is not adequate. But, if we instead use the corrected score for his 1955 group of sports champions (Number 2 in the above Table, see Section 13) then the chi-square goes up to 7, which is significant. The Mars-and-sports-champion effect has replicated. It's around a 1 in 100 level of significance, which is not much, but it will do.

Painters

We take one more example, this time a deficit. In 1975 MG asserted:

Only 203 of 1,473 great painters were born with Mars in sectors one or four. The odds against this: 200 to one.⁶

His original book of 1955 had 905 eminent painters scoring Mars in deficit (127 in Key Sectors), then in 1970 the Gauquelins had collected 1472 with much the same deficit (207 Mars in Key Sectors). Subtracting one from the other as before gives us the same 20% deficit, but the chi-square significance is just 3.7 which is merely borderline: not adequate as a significant replication.

The significance levels claimed by Michel Gauquelin were greatly mistaken.

 

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