I’ve never understood why people read horoscopes. It’s never been a temptation for me and always seemed absurd. Yet I hear there are people who believe in them. This is a true story that shows the power of persuasion when someone wants to believe.
A scientist places an ad in a Paris newspaper offering a free horoscope. He receives about 150 replies, each, as requested, detailing a place and time of birth. Every respondent is then sent the identical horoscope, along with a questionnaire asking how accurate the horoscope had been. Ninety-four percent of the respondents (and 90 percent of their families and friends) reply that they were at least recognizable in the horoscope. However, the horoscope was drawn up for a French serial killer. If an astrologer can get this far without even meeting his subjects, think how well someone sensitive to human nuances and no overly scrupulous might do.
—Carl Sagan, The Demon-Haunted World (Ballantine Books: 1995), pp. 242-243.