New Delhi, Aug. 13 -- they opened their horoscope apps.

For many, what they found felt uncannily, almost uncomfortably, accurate. A description of "creative tension brewing beneath the surface" for Scorpio. A warning to Virgo about "overthinking the unanswerable." A reminder to Leo, whose solar season this eclipse dramatically punctuates, that "you've been carrying other people's expectations." These phrases, generated by algorithms or written weeks in advance by staff astrologers, seemed to know something their readers had not told anyone else.

The feeling is not a coincidence, nor is it the influence of celestial bodies on human temperament. It is a well-documented psychological phenomenon that researchers have studied since 1948, whe...