The relationship between date of birth and individual differences in personality and general intelligence: A large-scale study
Peter Hartmann, Martin Reuterb and Helmuth Nyborga
We investigated the relationship between date of birth and individual differences in personality and intelligence in two large samples. The first sample consisted of 4000+ middle-aged male subjects from the Vietnam Experience Study; personality was measured by the MMPI items converted to EPQ (scales) and a large battery of cognitive tests were factored to derive general intelligence, g. The second sample consisted of 11,000+ young adults from the National Longitudinal Study of Youth from 1979. g was extracted from the ten subtests of the Armed Services Vocational Aptitude Battery.
In no cases did date of birth relate to individual differences in personality or general intelligence.
A further goal was to test Eysenck’s notion of possible relationships between date of birth and the popular Sun Signs in astrology. No support could be found for such associations.
We conclude that the present large-scale study provides no evidence for the existence of relevant relationships between date of birth and individual differences in personality and general intelligence.
Some remarks by leader of the study Peter Hartmann.
When considering the current scientific standing with respect to Sun signs, it becomes clear that there is little or no truth in [them]... This does not necessarily mean that all astrology is without truth, but only that the independent effect of Sun signs is most likely to be irrelevant.... As for the weekly horoscope based on mere Sun signs, then according to the current scientific standing, there is probably more truth in the comic strips.