The Short Version
This claim is false. Multiple rigorous scientific studies — including tests of over 152 experienced astrologers — show that birth charts cannot predict personality or life outcomes at rates better than random chance. No causal mechanism has ever been identified by which planetary positions at birth could influence a person. The scientific consensus from major institutions explicitly rejects astrology as a science. Any perceived accuracy is explained by well-documented cognitive biases like the Barnum effect, not actual celestial influence.