Updated: Mar 1, 2020
With the ring test, you take the pregnant woman's wedding ring (or other important ring) and tie it to a thread or string (some women use a strand of hair). The pregnant woman lies down, and you dangle the ring over her baby bump. If the ring swings in a circle, the baby will be a girl. If it swings back and forth, the baby is a boy. Although, as with many stories and folktales repeated over the years, some people say the opposite — a circle means a boy and back-and-forth means a girl.
We know, logically, that this isn't a scientific method of determining the sex of an unborn baby. In fact, the ring prediction method is so old and enduring that it's just about impossible to unearth how it even started. However, is there anything to these old wives' tales? Can they actually be accurate?
The Johns Hopkins School of Public Health was curious about this, too. In 1999, researchers there asked 104 pregnant women to predict the sex of their unborn babies, using whatever method they preferred — the ring test, or dreams and hunches. The women had a 55 percent success rate, which is the same as taking a wild guess. It seems the ring test, and others like it, don't really predict anything.
Like all superstitions or folklore, though, our brains are wired to want to believe. Cornell University psychology professor Tom Gilovich says that we, as humans, look for cause and effect where there is none. For example, someone we knew used the ring test, the ring swung in a circle, and our friend had a girl. That's coincidence, though — not magic.
So why do we keep doing it? Maybe because it's fun, maybe because it's wishful thinking. A 2010 study published in the Journal of Health Psychology, however, found something interesting. Pregnant women are more likely to listen to the opinions of their friends and family than to medical advice. Which may be why old wives' tales endure.