Many of the claims made about signs and personalities are vague and would fit many people under many different signs. Even professional astrologers, most of whom have nothing but disdain for Sun Sign Astrology, can't pick out a correct horoscope reading at better than a chance rate. Yet, astrology continues to maintain its popularity, despite the fact that there is scarcely a shred of scientific evidence in its flavor. Even the former First Lady of the United States, Nancy Reagan, and her husband, Ronald, consulted an astrologer while he was the leader of the free world. From which we can conclude that astrologers have more influence than the stars do.
Astrologers behave like psychologists when they make predictions about someone's life.
They use the laws of statistics to calculate the close outcome of certain actions. Their predictions are never exact. There are several reasons for the popularity of pseudosciences such as cosmobiology. The pragmatic fallacy is often committed in such matters because of the relative ease with which one can fit just about any piece of data to the theory. Analogies and metaphors are easy to see and are used to validate predictions.