Geophysical variables and behavior: LXXXVI. Geomagnetic activity as a partial parturitional trigger - Are male babies more affected than female babies?

The birth dates of 163 men and 245 women who were born between the years 19 58 and 1969 were extracted from our data base for first-year university stu dents. Daily aa values, measures of the amplitude of global geomagnetic act ivity, were obtained for the birthdays and for each of the seven days befor e and after the birthdays. Analyses of variance indicated no significant di fferences in the magnitudes of the geomagnetic activity during these 15 day s; however, men were born when the geomagnetic activity was significantly h igher than when the women were born. The effect, which was equivalent to a correlation coefficient of about .20, was largest for the day of birth and for the two or three days before birth. The means of the aa values for the day of birth and the day before birth for the men were about 7 nanoTesla hi gher than the values for the women.