In the paperwork of a national census, romance can be undone by a very unromantic mistake. One spouse fills out the household form, reaches the line for the other spouse, and repeats a birthday. In other records, January 1 appears because no exact date was known. Before the stars could be judged, David Voas had to deal with the odd little mess people leave in boxes.[2]
David Voas analyzed birthday data for more than 20 million husbands and wives in England and Wales and found no evidence that zodiac signs influence who marries whom, or who stays married.
The test came from the 2001 census of England and Wales, where Voas, then a senior research fellow at the University of Manchester’s Centre for Census and Survey Research, had access to an unusually large population for a very familiar claim. Horoscope columns may speak in the language of chemistry and fate, but this question could be counted: do particular sun signs marry each other more often than chance predicts?[1]
Voas put the scale plainly. If there were even a small tendency for Virgos to fancy Capricorns, or Libras to like Leos, it should appear in the marriage statistics. With about 10 million couples, an influence affecting only one pair in a thousand would mean roughly 10,000 extra couples in the favored sign combinations.[1]
At first glance, later summaries of the work describe a tempting wrinkle. The raw data seemed to show more same-sign couples than expected, including about 22,100 extra couples who shared a zodiac sign. That looked like the sort of pattern astrology would love to claim.[2]
The pattern became stranger when Voas looked more closely. It was especially strong among January-born Capricorns, not exactly a classic astrological prediction. A more detailed birthday table showed that couples were far more likely than expected to have the exact same birthday, and January 1 appeared unusually often, a known placeholder date when a real birthday was missing or uncertain.[2]
The census had already exposed similar household-form errors. Blossom’s summary notes that some couples were mistakenly recorded as same-sex partnerships because one spouse’s details had been entered for the other person. The birthday overlap pointed toward the same kind of human error: copied dates, placeholder dates, and forms filled out imperfectly at kitchen tables and desks.[2]
The Giant Magnifying Glass
After those errors were accounted for, the supposed zodiac effect disappeared into statistical noise. The University of Manchester account reported by Phys.org was blunt: the investigation “failed to reveal any evidence of attraction between star signs,” and the numbers were “just what we’d predict on the basis of chance,” Voas said.[1]
That mattered because everyday astrology often begins with sun signs. Voas acknowledged that astrologers might argue full birth charts are needed to predict personality accurately. But ordinary romantic advice often starts with the casual shorthand people actually use: “I’m a Gemini,” or “Never date a Scorpio.” If sun signs were useful for sizing up a mate, he argued, the census should have caught even a tiny signal.[1]
Voas did not expect the finding to empty the horoscope aisle. He said he was “under no illusion” that the results would undermine astrology’s popularity. At the time, a Google search for “love” and “astrology” produced about 3.5 million hits, and Linda Goodman’s astrology relationship books, including Sun Signs and Love Signs, had sold more than 100 million copies worldwide over the previous 40 years.[1]
The census could not say whether a person ever read a horoscope before agreeing to a date, nor whether a couple laughed about their signs over dinner. It could only ask whether the old zodiac map had left a visible mark across millions of marriages. In that enormous table, Aries, Taurus, Gemini, and the rest sat like labels around a circle, while the real traces were copied birthdays, January 1 placeholders, and ordinary people trying to finish a form.
