This is the most straightforward and direct way to test the accuracy of astrology, and it has been done by many researchers over the years.
One of the most famous studies of predictive astrology was conducted by the American psychologist John Dean in the 1930s.
Dean collected a large sample of horoscopes that had been cast for people at the time of their birth. He then followed the people over time and recorded their life events. He found that there was no correlation between the predictions made in the horoscopes and the actual outcomes of the people's lives.
Another study of predictive astrology was conducted by the British astronomer Michael Gauquelin in the 1950s and 1960s.
Gauquelin collected a large sample of horoscopes of famous people and found that there was a statistically significant correlation between the positions of the planets at the time of birth and the careers of the people. For example, he found that people who were born with the planet Mars in the first house of their horoscope were more likely to be athletes, while people who were born with the planet Venus in the first house of their horoscope were more likely to be artists.
However, Gauquelin's findings have been criticized by other researchers, who argue that they are not statistically significant and that they can be explained by chance.
Overall, the evidence for the accuracy of predictive astrology is mixed. Some studies have found evidence that astrology can predict future events, while other studies have found no evidence to support this claim. More research is needed to determine whether or not astrology is a valid form of divination.