In a range of studies no significant astrological correlations were found, but some diurnal effects were claimed.
2,000 subjects and 52,188 personality traits developed from biographies.
no correlation was found between the character traits of the subjects and the signs under which they were born.
The proportion found was 22%, whereas 17% might be expected by chance.
There is no effect for successful athletes in general.
A study in the US (Kurtz, Zelen, and Abell, SI 1979/80 4:2, 19) failed to replicate the effect.
Does the result have any predictive value? In a large sample of births, for those with Mars rising, could you predict the Olympic gold medalists?
and the answer is: NO.