A re-assessment of Jung’s astrological test of synchronicity provides no convincing reason to believe in either. Nevertheless, precisely because of this, Jung’s results still provide food for thought.

J. F. Ruis compared birth frequencies between males and females of ordinary people (Gauquelin data) across planetary sectors and claimed that certain frequencies differed significantly. Since the dates of birth in his male and female sub samples had not been matched, the result might be due to an astronomical-demographical artefact. The present study tries to replicate Ruis’ result using the same data with male and female sub samples matched for date of birth (n+ 7,593) each. Each sub sample was divided using the median birth day as the dividing point, into two successive cohorts. For each cohort the male proportion of births, indicating the gender difference, was determined across 36 sectors of 5 planets. If gender differences exist they should be stable across successive cohorts, but gender differences in the first cohort did not reoccur in the subsequent cohort. This was revealed by correlations. The observed lack of stable differences cannot be attributed to the method since the same method successfully demonstrated stability in identifying Mars-prone professionals and ordinary people. The finding of Ruis is thus most probably due to an astronomical-demographical artefact.

The Gauquelin distributions for professionals are examined and the chance of finding such close clustering of the phase angles for the 3rd and 4th harmonics is shown to be very small. An experiment of simulating “noise” addition to the data (to resemble the tampering noted by Dean) is described and it is shown that the phase angles are robust against noise. A speculation by Addey that the 3rd and 4th harmonics represent subsets of one population is examined, and it is shown that the ratios of the amplitudes of the 3rd and 4th harmonics for each of the professional groups varies widely (as would follow if Addy’s speculation is true).